Grade 9 Mathematics Pythagorean Relation
cvcv
Grade 9
රව් වම්බන්ධය
Reading material
Mathematics
Unit 19
Pythagorean Relation
Pythagorean Relation
W. T. Maduranga Premanath
R/Dharmaloka Maha Vidyalaya
Pelmadulla
1
, Grade 9 Mathematics Pythagorean Relation
By studying this lesson, you will be able to;
❑ Develop the Pythagorean relation by means of a right-angled triangle,
❑ Solve problems related to the Pythagorean relation.
19.1. Classifying triangles according to the magnitude of interior angles.
The triangles can be classified in to three types according to the magnitude of the largest
angle in the triangle.
Acute angled triangle Right angled triangle Obtuse angled triangle
If the largest angle in a If the largest angle in a If the largest angle in a
triangle is an acute angle, triangle is a right angle, triangle is an obtuse angle,
that triangle is known as that triangle is known as that triangle is known as
an acute angled triangle. a right-angled triangle. an obtuse angled triangle.
19.2. Identifying the characteristics of a right-angled triangle.
The side opposite to the right angle (the longest side) of any right-angled triangle is known
as the hypotenuse. The other two sides which contain the right angle is known as the sides
include the right angle.
2
cvcv
Grade 9
රව් වම්බන්ධය
Reading material
Mathematics
Unit 19
Pythagorean Relation
Pythagorean Relation
W. T. Maduranga Premanath
R/Dharmaloka Maha Vidyalaya
Pelmadulla
1
, Grade 9 Mathematics Pythagorean Relation
By studying this lesson, you will be able to;
❑ Develop the Pythagorean relation by means of a right-angled triangle,
❑ Solve problems related to the Pythagorean relation.
19.1. Classifying triangles according to the magnitude of interior angles.
The triangles can be classified in to three types according to the magnitude of the largest
angle in the triangle.
Acute angled triangle Right angled triangle Obtuse angled triangle
If the largest angle in a If the largest angle in a If the largest angle in a
triangle is an acute angle, triangle is a right angle, triangle is an obtuse angle,
that triangle is known as that triangle is known as that triangle is known as
an acute angled triangle. a right-angled triangle. an obtuse angled triangle.
19.2. Identifying the characteristics of a right-angled triangle.
The side opposite to the right angle (the longest side) of any right-angled triangle is known
as the hypotenuse. The other two sides which contain the right angle is known as the sides
include the right angle.
2
