CHAPTER 1 br
Section 1.1 Solutions --------------------------------------------------------------------------------
br br br
1 x 1 x
b r b r b r br b r b r b r
1. Solve for x:
b r br br b r br 2. Solve for x:
b r br br b r br
2 360∘ 4 360∘
360∘ 2x, so that x 180∘ .
br br b r br b r br br br 360∘ 4x, so that x 90∘ .
b r br b r br b r br br br
1 x 2 x
3. Solve for x: 4. Solve for x:
b r b r b r b r b r b r
b r br br b r br br b r br br b r b r br
3 360∘ 3 360∘
360∘ 3x, so that x 120∘ . (Note
br br br br b r br br br br 720∘ 2(360∘ ) 3x, so that x 240∘ . (
br br br br br br br b r br br br br
: The angle has a negative measure si
br br br br br br br Note: The angle has a negative measur
b r br br br br b r
nce it is a clockwise rotation.)
br br br br br e since it is a clockwise rotation.)
br br br br br br
5 x 7 x
b r b r b r br brb r b r b r
5. Solve for x:
b r br br b r br 6. Solve for x:
b r br br b r br
6 360∘ 12 360∘
1800∘ 5(360∘ ) 6x, so that x 300∘ .
br br br br br br br b r br br br 2520∘ 7(360∘ ) 12x, so that x 210∘ .
br br br br br b r br b r br br br
4 x 5 x
7. Solve for x: 8. Solve for x:
br b r b r b r b r b r b r
b r br br b r br br b r br br b r br br
5 360∘ 9 360∘
1440∘ 4(360∘ ) 5x, so that
br br br br br br br 1800∘ 5(360∘ ) 9x, so that
br br br br br br br
x 288∘ .
br br br x 200∘ .
br br br
(Note: The angle has a negative meas
b r br br br br br (Note: The angle has a negative measur
b r br br br br br
ure since it is a clockwise rotation.)
br br br br br br e since it is a clockwise rotation.)
br br br br br br
9. 10.
a) complement: 90∘ 18∘ 72∘ b r br b r b r a) complement: 90∘ 39∘ 51∘ b r br br b r b r
b) supplement: 180∘ 18∘ 162∘ b r br b r b r b) supplement: 180∘ 39∘ 141∘ b r br br b r b r
11. 12.
a) complement: 90∘ 42∘ 48∘ b r br br b r b r a) complement: 90∘ 57∘ 33∘ b r br br b r b r
b) supplement: 180∘ 42∘ 138∘ b r br br b r b r b) supplement: 180∘ 57∘ 123∘ b r br br b r b r
1
,Chapter 1 br
13. 14.
a) complement: 90∘ 89∘ 1∘ b r br br b r b r a) complement: 90∘ 75∘ 15∘ b r br br b r b r
b) supplement: 180∘ 89∘ 91∘ b r br br b r b r b) supplement: 180∘ 75∘ 105∘ b r br br b r b r
15. Since the angles with measures 4x∘ and 6x∘ are assumed to be complement
b r br br br br br b r b r br br br br br
ary, we know that 4x∘ 6x∘ 90∘. Simplifying this yields
br br br br br br br br b r br br
10x∘ 90∘, br br b
r b r so that x 9. So, the two angles have measures 36∘and 54∘ .
br b r br br b r br br br br br b r br br
16. Since the angles with measures 3x∘ and 15x∘ are assumed to be supplement
b r br br br br br b r b r br br br br br
ary, we know that 3x∘ 15x∘ 180∘. Simplifying this yields
br br br br br br br br b r br br
18x∘ 180∘, so that br br br br b r x 10. So, the two angles have measures 30∘ and 150∘ .
br br b r br br br br br b r br br br
17. Since the angles with measures 8x∘ and 4x∘ are assumed to be supplementar
b r br br br br b r br b r br br br br br
y, we know that 8x∘ 4x∘ 180∘. Simplifying this yields
br br br br br br br br b r br br
12x∘ 180∘, br br b r so that x 15. So, the two angles have measures 60∘ and 120∘ .
br b r br br b r br br br br br b r br br br
18. Since the angles with measures 3x 15∘and 10x 10∘are assumed to be com
b r br br br br b r br b
r b r br b
r br br br br
plementary, we know that 3x 15∘ 10x 10∘ 90∘. Simplifying this yields
br br br br br br br br br br b r br br
13x 25∘ 90∘, br br br br b r so that 13x∘ 65∘ and thus, x 5. So, the two angles have measu
br br br br b r br b r br br b r br br br br br
res 30∘and 60∘ .
b r br br
19. Since 180∘, we know th
b r br br br br br b r br b r br br 20. Since 180∘, we know tha
b r br br br br br b r br b r br br
at t
1 17∘ –33∘ 180∘ and so, 30∘ . 1 10∘ –45∘ 180∘ and so, 25∘ .
– –
br br br br br br br b r br br br br br br br br br br br br br br
br br
br150∘ br155∘
21. Since 180∘, we know th
b r br br br br br b r br b r br br 22. Since 180∘, we know tha
b r br br br br br b r br b r br br
at t
4 180∘ and so, 30∘.
br br br br br br br br br br br br br 3 180∘ and so, 36∘.
br br br br br br br br br br br br br
–– –– –– ––
br6br br5
Thus, 4 120∘ and 30∘ .
b r b r br b r br b r br b r br b r br br Thus, 3 108∘ and 36∘ .
b r b r br b r br b r br b r br b r br br
2
, Section 1.1br
23. 180∘ 53.3∘ 23.6∘ 103.1∘
b r br br br br br br br br br 24. 180∘ 105.6∘ 13.2∘ 61.2∘
b r br br br br br br br br
25. Since this is a right triangle, we know from the Pythagorean Theorem that a
b r br br br br br br br br br br br br br
2
b2 c2. Using the given information, this becomes 42 32 c2, which simpl
br br br br b r br br br br br b r br br br br br b r br
ifies to c2 25, so we conclude that c 5.
br b r br br b r br br br b r br br br
26. Since this is a right triangle, we know from the Pythagorean Theorem that
b r br br br br br br br br br br br br
a2 b2 c2. Using the given information, this becomes 32 32 c2, which simp
br br b r br b r br br br br br b r br br b r br br b r br
lifies to c2 18, so we conclude that c
br b r b r br b r br br br b r br b r b r 18 3 2 . br br b r br
27. Since this is a right triangle, we know from the Pythagorean Theorem that a
b r br br br br br br br br br br br br br
2
b2 c2. Using the given information, this becomes 62 b2 102, which sim
br br br br b r br br br br br b r br br br br br b r br
plifies to 36 b2 100 and then to, b2 64, so we conclude that b 8 .
br b r br br br br br br br br br br b r br br br b r br br br
28. Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r b r br b r b r b r b r b r
a2 b2 c2. Using the given information, this becomes a2 72 122, which
br br b r br b r br br br br br b r br br b r br br b r
simplifies to a2 95, so we conclude that a 95 .
br br b r br br b r br br br b r br br
29. Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r b r br b r b r b r b r b r
a2 b2 c2. Using the given information, this becomes 82 52 c2, which
br br b r br b r br br br br br b r br br b r br br b r br
simplifies to c2 89, so we conclude that c br b r br br b r br br br b r br 89 . br
30. Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r b r br b r b r b r b r b r
a2 b2 c2. Using the given information, this becomes 62 52 c2, which
br br b r br b r br br br br br b r br br b r br br b r br
simplifies to c2 61, so we conclude that c br b r br br b r br br br b r br 61 . br
31. Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r b r br b r b r b r b r b r
a2 b2 c2. Using the given information, this becomes 72 b2 112, which
br br b r br b r br br br br br b r br br b r br br b r
simplifies to b2 72, so we conclude that b 72 6 2 .
br br b r br br b r br br br b r br br br b r br
32. Since this is a right triangle, we know from the Pythagorean Theorem that
br br br br br br br br br br br br br
a2 b2 c2. Using the given information, this becomes a2 52 92, which
br br b r br b r br br br br br b r br br b r br br b r br
simplifies to a2 56, so we conclude that a br b r br br b r br br br b r br 56 2 14 . br br b r br
3
, Chapter 1 br
33. b r Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r br b r b r b r b r b r
7
2b
a2 b2 c2. Using the given information, this becomes a2 52, which simpli
r
br br b r br b r br br br br br b r br br br br br b r br
b r
fies to a2 18, so we conclude that a
br b r b r br b r br br br b r br b r b r 18 3 2 . br br b r br
34. Since this is a right triangle, we know from the Pythagorean Theorem that
br br br br br br br br br br br br br
a2 b2 c2. Using the given information, this becomes 52 b2 102, which
br br b r br b r br br br br br b r br br b r br br b r
simplifies to b2 75, so we conclude that b 75 5 3 .
br br b r br br b r br br br b r br br br b r br
35. If x 10 in., then the hypotenuse
b r b r br br br b r br br br 36. If x 8 m, then the hypotenuse of th
b r b r br br br b r br br br br
of this triangle has length is triangle has length 8 2 11.31 m .
br br br br
br br br b r b r br br br br
10 2 14.14 in.
b r br br br
37. Let x be the length of a leg in the given 45∘ 45∘ 90∘ triangle. If the hypo
b r br br br br br br br br br br b r br br br br br b r br br
tenuse of this triangle has length 2 2 cm, then
br br br br br b r b r b r b r
2 x 2 2, so that x 2.
br br br b r br br br br br br
Hence, the length of each of the two legs is 2 cm .
br br br br br br br br br b r br br
38. Let x be the length of a leg in the given 45∘ 45∘ 90∘ triangle. If the hypotenuse
br br br br br br br br br br br br br br br br b r b r br br
10 10
of this triangle has length 10 ft., then 2 x 10, so that x 5.
b r b r br
br br br br br br br br b r b r br br br br br
2 2
Hence, the length of each of the two legs is br br br br br br br br br 5 ft. br
39. The hypotenuse has length
b r br br br
40. Since br 2x 6m x br br br br br br
6 2
b r b r 3 2m,
br b r
2
2 4 2 in. 8in.
br b r b r br br br br
each leg has length 3 2 m. br br br br b r b r
41. Since the lengths of the two legs of the given30∘ 60∘ 90∘ triangle are x an
b r br br br br br br br br br br b r br b r br b r br br br
d 3 x, the shorter leg must have length x. Hence, using the given information,
br br b r b r b r b r b r b r br b r b r b r b r b r
we b r
know that x 5 m. Thus, the two legs have lengths 5 m and 5 3 8.66 m, and t
br b r br br br b r br br br br br b r br br b r b r br br br b r br
he hypotenuse has length 10 m.
br br br br br
42. Since the lengths of the two legs of the given 30∘ 60∘ 90∘ triangle are x a
b r br br br br br br br br br b r br br b r br b r br br br
nd 3 x, the shorter leg must have length x. Hence, using the given informatio
br br b r b r b r b r b r b r br b r b r b r b r b r
n, we b r
know that x 9ft. Thus, the two legs have lengths 9 ft. and 9 3 15.59 ft., and t
br b r br br br b r br br br br br b r br br b r b r br br br b r br
4
Section 1.1 Solutions --------------------------------------------------------------------------------
br br br
1 x 1 x
b r b r b r br b r b r b r
1. Solve for x:
b r br br b r br 2. Solve for x:
b r br br b r br
2 360∘ 4 360∘
360∘ 2x, so that x 180∘ .
br br b r br b r br br br 360∘ 4x, so that x 90∘ .
b r br b r br b r br br br
1 x 2 x
3. Solve for x: 4. Solve for x:
b r b r b r b r b r b r
b r br br b r br br b r br br b r b r br
3 360∘ 3 360∘
360∘ 3x, so that x 120∘ . (Note
br br br br b r br br br br 720∘ 2(360∘ ) 3x, so that x 240∘ . (
br br br br br br br b r br br br br
: The angle has a negative measure si
br br br br br br br Note: The angle has a negative measur
b r br br br br b r
nce it is a clockwise rotation.)
br br br br br e since it is a clockwise rotation.)
br br br br br br
5 x 7 x
b r b r b r br brb r b r b r
5. Solve for x:
b r br br b r br 6. Solve for x:
b r br br b r br
6 360∘ 12 360∘
1800∘ 5(360∘ ) 6x, so that x 300∘ .
br br br br br br br b r br br br 2520∘ 7(360∘ ) 12x, so that x 210∘ .
br br br br br b r br b r br br br
4 x 5 x
7. Solve for x: 8. Solve for x:
br b r b r b r b r b r b r
b r br br b r br br b r br br b r br br
5 360∘ 9 360∘
1440∘ 4(360∘ ) 5x, so that
br br br br br br br 1800∘ 5(360∘ ) 9x, so that
br br br br br br br
x 288∘ .
br br br x 200∘ .
br br br
(Note: The angle has a negative meas
b r br br br br br (Note: The angle has a negative measur
b r br br br br br
ure since it is a clockwise rotation.)
br br br br br br e since it is a clockwise rotation.)
br br br br br br
9. 10.
a) complement: 90∘ 18∘ 72∘ b r br b r b r a) complement: 90∘ 39∘ 51∘ b r br br b r b r
b) supplement: 180∘ 18∘ 162∘ b r br b r b r b) supplement: 180∘ 39∘ 141∘ b r br br b r b r
11. 12.
a) complement: 90∘ 42∘ 48∘ b r br br b r b r a) complement: 90∘ 57∘ 33∘ b r br br b r b r
b) supplement: 180∘ 42∘ 138∘ b r br br b r b r b) supplement: 180∘ 57∘ 123∘ b r br br b r b r
1
,Chapter 1 br
13. 14.
a) complement: 90∘ 89∘ 1∘ b r br br b r b r a) complement: 90∘ 75∘ 15∘ b r br br b r b r
b) supplement: 180∘ 89∘ 91∘ b r br br b r b r b) supplement: 180∘ 75∘ 105∘ b r br br b r b r
15. Since the angles with measures 4x∘ and 6x∘ are assumed to be complement
b r br br br br br b r b r br br br br br
ary, we know that 4x∘ 6x∘ 90∘. Simplifying this yields
br br br br br br br br b r br br
10x∘ 90∘, br br b
r b r so that x 9. So, the two angles have measures 36∘and 54∘ .
br b r br br b r br br br br br b r br br
16. Since the angles with measures 3x∘ and 15x∘ are assumed to be supplement
b r br br br br br b r b r br br br br br
ary, we know that 3x∘ 15x∘ 180∘. Simplifying this yields
br br br br br br br br b r br br
18x∘ 180∘, so that br br br br b r x 10. So, the two angles have measures 30∘ and 150∘ .
br br b r br br br br br b r br br br
17. Since the angles with measures 8x∘ and 4x∘ are assumed to be supplementar
b r br br br br b r br b r br br br br br
y, we know that 8x∘ 4x∘ 180∘. Simplifying this yields
br br br br br br br br b r br br
12x∘ 180∘, br br b r so that x 15. So, the two angles have measures 60∘ and 120∘ .
br b r br br b r br br br br br b r br br br
18. Since the angles with measures 3x 15∘and 10x 10∘are assumed to be com
b r br br br br b r br b
r b r br b
r br br br br
plementary, we know that 3x 15∘ 10x 10∘ 90∘. Simplifying this yields
br br br br br br br br br br b r br br
13x 25∘ 90∘, br br br br b r so that 13x∘ 65∘ and thus, x 5. So, the two angles have measu
br br br br b r br b r br br b r br br br br br
res 30∘and 60∘ .
b r br br
19. Since 180∘, we know th
b r br br br br br b r br b r br br 20. Since 180∘, we know tha
b r br br br br br b r br b r br br
at t
1 17∘ –33∘ 180∘ and so, 30∘ . 1 10∘ –45∘ 180∘ and so, 25∘ .
– –
br br br br br br br b r br br br br br br br br br br br br br br
br br
br150∘ br155∘
21. Since 180∘, we know th
b r br br br br br b r br b r br br 22. Since 180∘, we know tha
b r br br br br br b r br b r br br
at t
4 180∘ and so, 30∘.
br br br br br br br br br br br br br 3 180∘ and so, 36∘.
br br br br br br br br br br br br br
–– –– –– ––
br6br br5
Thus, 4 120∘ and 30∘ .
b r b r br b r br b r br b r br b r br br Thus, 3 108∘ and 36∘ .
b r b r br b r br b r br b r br b r br br
2
, Section 1.1br
23. 180∘ 53.3∘ 23.6∘ 103.1∘
b r br br br br br br br br br 24. 180∘ 105.6∘ 13.2∘ 61.2∘
b r br br br br br br br br
25. Since this is a right triangle, we know from the Pythagorean Theorem that a
b r br br br br br br br br br br br br br
2
b2 c2. Using the given information, this becomes 42 32 c2, which simpl
br br br br b r br br br br br b r br br br br br b r br
ifies to c2 25, so we conclude that c 5.
br b r br br b r br br br b r br br br
26. Since this is a right triangle, we know from the Pythagorean Theorem that
b r br br br br br br br br br br br br
a2 b2 c2. Using the given information, this becomes 32 32 c2, which simp
br br b r br b r br br br br br b r br br b r br br b r br
lifies to c2 18, so we conclude that c
br b r b r br b r br br br b r br b r b r 18 3 2 . br br b r br
27. Since this is a right triangle, we know from the Pythagorean Theorem that a
b r br br br br br br br br br br br br br
2
b2 c2. Using the given information, this becomes 62 b2 102, which sim
br br br br b r br br br br br b r br br br br br b r br
plifies to 36 b2 100 and then to, b2 64, so we conclude that b 8 .
br b r br br br br br br br br br br b r br br br b r br br br
28. Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r b r br b r b r b r b r b r
a2 b2 c2. Using the given information, this becomes a2 72 122, which
br br b r br b r br br br br br b r br br b r br br b r
simplifies to a2 95, so we conclude that a 95 .
br br b r br br b r br br br b r br br
29. Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r b r br b r b r b r b r b r
a2 b2 c2. Using the given information, this becomes 82 52 c2, which
br br b r br b r br br br br br b r br br b r br br b r br
simplifies to c2 89, so we conclude that c br b r br br b r br br br b r br 89 . br
30. Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r b r br b r b r b r b r b r
a2 b2 c2. Using the given information, this becomes 62 52 c2, which
br br b r br b r br br br br br b r br br b r br br b r br
simplifies to c2 61, so we conclude that c br b r br br b r br br br b r br 61 . br
31. Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r b r br b r b r b r b r b r
a2 b2 c2. Using the given information, this becomes 72 b2 112, which
br br b r br b r br br br br br b r br br b r br br b r
simplifies to b2 72, so we conclude that b 72 6 2 .
br br b r br br b r br br br b r br br br b r br
32. Since this is a right triangle, we know from the Pythagorean Theorem that
br br br br br br br br br br br br br
a2 b2 c2. Using the given information, this becomes a2 52 92, which
br br b r br b r br br br br br b r br br b r br br b r br
simplifies to a2 56, so we conclude that a br b r br br b r br br br b r br 56 2 14 . br br b r br
3
, Chapter 1 br
33. b r Since this is a right triangle, we know from the Pythagorean Theorem that
b r b r b r b r b r b r br b r b r b r b r b r
7
2b
a2 b2 c2. Using the given information, this becomes a2 52, which simpli
r
br br b r br b r br br br br br b r br br br br br b r br
b r
fies to a2 18, so we conclude that a
br b r b r br b r br br br b r br b r b r 18 3 2 . br br b r br
34. Since this is a right triangle, we know from the Pythagorean Theorem that
br br br br br br br br br br br br br
a2 b2 c2. Using the given information, this becomes 52 b2 102, which
br br b r br b r br br br br br b r br br b r br br b r
simplifies to b2 75, so we conclude that b 75 5 3 .
br br b r br br b r br br br b r br br br b r br
35. If x 10 in., then the hypotenuse
b r b r br br br b r br br br 36. If x 8 m, then the hypotenuse of th
b r b r br br br b r br br br br
of this triangle has length is triangle has length 8 2 11.31 m .
br br br br
br br br b r b r br br br br
10 2 14.14 in.
b r br br br
37. Let x be the length of a leg in the given 45∘ 45∘ 90∘ triangle. If the hypo
b r br br br br br br br br br br b r br br br br br b r br br
tenuse of this triangle has length 2 2 cm, then
br br br br br b r b r b r b r
2 x 2 2, so that x 2.
br br br b r br br br br br br
Hence, the length of each of the two legs is 2 cm .
br br br br br br br br br b r br br
38. Let x be the length of a leg in the given 45∘ 45∘ 90∘ triangle. If the hypotenuse
br br br br br br br br br br br br br br br br b r b r br br
10 10
of this triangle has length 10 ft., then 2 x 10, so that x 5.
b r b r br
br br br br br br br br b r b r br br br br br
2 2
Hence, the length of each of the two legs is br br br br br br br br br 5 ft. br
39. The hypotenuse has length
b r br br br
40. Since br 2x 6m x br br br br br br
6 2
b r b r 3 2m,
br b r
2
2 4 2 in. 8in.
br b r b r br br br br
each leg has length 3 2 m. br br br br b r b r
41. Since the lengths of the two legs of the given30∘ 60∘ 90∘ triangle are x an
b r br br br br br br br br br br b r br b r br b r br br br
d 3 x, the shorter leg must have length x. Hence, using the given information,
br br b r b r b r b r b r b r br b r b r b r b r b r
we b r
know that x 5 m. Thus, the two legs have lengths 5 m and 5 3 8.66 m, and t
br b r br br br b r br br br br br b r br br b r b r br br br b r br
he hypotenuse has length 10 m.
br br br br br
42. Since the lengths of the two legs of the given 30∘ 60∘ 90∘ triangle are x a
b r br br br br br br br br br b r br br b r br b r br br br
nd 3 x, the shorter leg must have length x. Hence, using the given informatio
br br b r b r b r b r b r b r br b r b r b r b r b r
n, we b r
know that x 9ft. Thus, the two legs have lengths 9 ft. and 9 3 15.59 ft., and t
br b r br br br b r br br br br br b r br br b r b r br br br b r br
4