Question

The angles of a triangle are in the ratio 7 : 9 : 2 . The measure of the smallest angle is _______.

• A. 30°
• B. 10°
• C. 25°
• D. 20°

Answer 1

The correct option is D

20°

Sum of all the interior angles of a triangle = 180°

Let the measure of angles be 7x, 9x and 2x.

$\Rightarrow$ 7x + 9x + 2x = 180°

$\Rightarrow$ 18x = 180°

$\Rightarrow$ $x=\frac{180°}{18}$

$\Rightarrow$ $x=10°$

Hence, the measure of the smallest angle $=2\times x=2\times 10=20°$