Question

Say True or False:
In a triangle, if a pair of angles is complementary, then the triangle is a right-angled triangle.

• A. True
• B. False

Answer 1

The correct option is A

True

Consider a triangle ABC,

and Let A and C be a pair of angles for which they are complementary, which means $\angle A$ +$\angle C$ = ${90}^{\circ }$.
Thus $\angle B$ = ${90}^{\circ }$. (As, sum of angles of a triangle = ${180}^{\circ }$)
Hence, the triangle is right angled triangle.