Geometry: Wells: Study Guide Questions and
Verified Answers, 100% Guarantee
Midline Theorem - A segment joining the midpoints of 2 sides of a triangle is parallel to
the 3rd side and its length is 1/2 the length of the third side
Sum of interior angles: Si = - (n-2)x180
To find how many Diagnols are in a polygon (n=sides) - n(n-3)/2
The measure of E (each exterior angle) of an equiangular polygon - 360/n
Means-Extremes Prduct thm - In a proportion the product of the means is equal to the
product of the extremes (cross multiplication)
Means-Extremes Ratio thm - If the product of a pair of nonzero numbers is equal to the
product of another pair of nonzero numbers then either pair of numbers may be made the
extremes and the other pair the means of proportion
Geometric mean/Mean proportional - when the means of a proportion are equal
arithmetic mean (average) - sum of values/number of values
The ratios of the perimeters of 2 similar polygons equals - the ratio of any pair of
corresponding sides
Ways to prove triangles congruent - SSS, SAS, ASA, AAS, HL
, Ways to prove triangles similar - AA, SSS, SAS
Side splitter - If a line is parallel to one side of a triangle and intersects the other two
sides, it divides those two sides proportionaly
if 3 or more parallel lines are intersected by 2 transversals - the parallel lines divide the
transversals proportionally
Angle Bisector Theorem - If a ray bisects an angle of a triangle, it divides the opposite
side into segments that are proportional to the adjacent sides.
piece #1/side adjacent to piece #1. = piece #2/side adjacent to piece #2. or piece 1/piece 2 = side
adjacent piece 1/ side adjacent piece 2
When to use "plus minus sign" in radicals - When the problem involves x (or another
variable)
LHP - Either leg is the mean proportional between the hypotenuse and the piece of the
hypotenuse and the piece of the hypotenuse adjeacent ot that leg
ASH - the altitude is the mean proportional between the piece(sections) of the hypotenuse
**acute angle** - An angle whose measure is greater than 0 and less than 90. (p. 11)
**acute triangle** - A triangle in which all three angles are acute. (p. 143)
**alternate exterior angles** - A pair of angles in the exterior of a figure formed by two
lines and a transversal, lying on alternate sides of the transversal and having different vertices.
(p. 194)
Verified Answers, 100% Guarantee
Midline Theorem - A segment joining the midpoints of 2 sides of a triangle is parallel to
the 3rd side and its length is 1/2 the length of the third side
Sum of interior angles: Si = - (n-2)x180
To find how many Diagnols are in a polygon (n=sides) - n(n-3)/2
The measure of E (each exterior angle) of an equiangular polygon - 360/n
Means-Extremes Prduct thm - In a proportion the product of the means is equal to the
product of the extremes (cross multiplication)
Means-Extremes Ratio thm - If the product of a pair of nonzero numbers is equal to the
product of another pair of nonzero numbers then either pair of numbers may be made the
extremes and the other pair the means of proportion
Geometric mean/Mean proportional - when the means of a proportion are equal
arithmetic mean (average) - sum of values/number of values
The ratios of the perimeters of 2 similar polygons equals - the ratio of any pair of
corresponding sides
Ways to prove triangles congruent - SSS, SAS, ASA, AAS, HL
, Ways to prove triangles similar - AA, SSS, SAS
Side splitter - If a line is parallel to one side of a triangle and intersects the other two
sides, it divides those two sides proportionaly
if 3 or more parallel lines are intersected by 2 transversals - the parallel lines divide the
transversals proportionally
Angle Bisector Theorem - If a ray bisects an angle of a triangle, it divides the opposite
side into segments that are proportional to the adjacent sides.
piece #1/side adjacent to piece #1. = piece #2/side adjacent to piece #2. or piece 1/piece 2 = side
adjacent piece 1/ side adjacent piece 2
When to use "plus minus sign" in radicals - When the problem involves x (or another
variable)
LHP - Either leg is the mean proportional between the hypotenuse and the piece of the
hypotenuse and the piece of the hypotenuse adjeacent ot that leg
ASH - the altitude is the mean proportional between the piece(sections) of the hypotenuse
**acute angle** - An angle whose measure is greater than 0 and less than 90. (p. 11)
**acute triangle** - A triangle in which all three angles are acute. (p. 143)
**alternate exterior angles** - A pair of angles in the exterior of a figure formed by two
lines and a transversal, lying on alternate sides of the transversal and having different vertices.
(p. 194)
