RRB Group-D Model Paper 20 with answers for online practice

Let the three angles are x, y, z.
One angle of a triangle is equal to the sum of the other two equal angles.
x = (y + z)
We know that sum of three angles of a triangle = 180°
So, we write,
x + y + z = 180°
⇒ x + x = 180°
⇒ x = 180°/2 = 90°
As we are seeing that one of the angles of the triangle is right angle then it is right angled triangle.