Question

In an isosceles triangle if one of the angle measures 140${}^0$, find the measure of the smallest angle.

• A. 10⁰
• B. 20⁰
• C. 30⁰
• D. 40⁰
• E. 50⁰

Answer 1

The correct option is B

20⁰

Given an isosceles triangle and we know that the sum of the angles in a triangle is 180${}^0$

Let the other angle measures `x' degrees

2x +140${}^0$ =180${}^0$

$\Rightarrow$ x = 20${}^0$