Question

The angles of a triangle are in the ratio 1 : 4 : 5.

Work out the size of the smallest angle?

Answer 1

18°

Explanation:

sum the parts of the ratio, 1 + 4 + 5 = 10 parts

The sum of the 3 angles in a triangle = 180° , then

180° ÷ 10 = 18° ← value of 1 part of the ratio

Since 1 is the smallest part of the ratio it represents the smallest angle, thus

smallest angle = 18°