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SAI International School

CLASS – VII

Mathematics

Chapter-6: Triangle and its properties-4
Lesson Notes – 4

SUBTOPIC: Right-angled triangles and Pythagoras property

Right-Angled Triangles and Pythagoras Property:

 In a right angle triangle, the side opposite to the right angle is called the hypotenuse.
 The other two sides are known as the base and perpendicular of the right-angled triangle.
 Hypotenuse is the longest side of the triangle, because the side opposite to the greatest
angle is the longest.

Pythagoras Theorem:

In a right-angled triangle, the square of the hypotenuse is equal to the sum of the squares of
base and perpendicular.

2
2
2
i.e (Hypotenuse) = (Base) + (Perpendicular)
If a triangle holds Pythagoras property, then the triangle must be right-angled.

2
2
2
AC =AB +BC
2
2
2
⇒5 =4 +3 .