Question

In a triangle, Angle A is 54 degrees, Angle B is twice the size of Angle C. What is the size of Angle B?

Answer 1

The size of Angle B is 84 degrees.

Explanation:

In a triangle, the 3 interior angles always add to 180 degrees.

Angle A = 54 degrees

Angle B = 2C

Angle C = C

A + B + C = 180

54 + 2C + C = 180

54 + 3C = 180

54 - 54 + 3C = 180 - 54

3C = 126

3C/3 = 126/3

C = 42

Angle A = 54 degrees

Angle B = 2(42) = 84

Angle C = 42

Check:

54 + 84 + 42 = 180

180 = 180