Question

Find the measure of angle C of a triangle ABC, if: m∠A = α, m∠B = 2α

Answer 1

angle A+ angle B + angle c = 180 ( angle sum property of triangle )
a + 2a + angle c = 180
angle c = 180-3a

Answer 2

Answer:

The measure angle C of a triangle ABC is $180^o-3 \alpha$.

Step-by-step explanation:

Given a triangle ABC.

The measure of angle A is $\angle A=\alpha$

The measure of angle B is $\angle B=2\alpha$  

According to the angle sum property of a triangle, the sum of angles in a triangle is equal to 180°.

Therefore, the sum of the angles of the given triangle ABC is

$\angle A + \angle B +\angle C = 180^o$

$\implies \alpha + 2 \alpha +\angle C = 180^o$

$\implies 3 \alpha +\angle C = 180^o$

$\implies \angle C = 180^o-3 \alpha$

Therefore, the measure angle C of a triangle ABC is $180^o-3 \alpha$.