Question

Prove that in a triangle if one of the angles is equal to the other two angles, then it is a right angled triangle .​

Answer 1

Step-by-step explanation:

Let "a" be the measure of the angle A;

Let "b" be the measure of the angle B;

Let "c" be the measure of the angle C.

Then

a + b + c = 180, (1)

a + b = c. (2) (given).

Add the equation (1) and (2). You will get

2(a+b) + c = 180 + c.

Simplify:

2(a+b) = 180 ---> a + b = 180/2=90

hope this will help you (:

Answer 2

Answer:

Let ABC be triangle with angle A as 90deg.

Step-by-step explanation:

Given : angle A = angle B + angle C

angle A + angle B + angle C = 180deg { angle sum property of triangle }

angle A + angle A = 180deg { since angle A = angle B + angle C }

2 angle A = 180deg

angle A = 90deg.

HENCE PROVED