Question

What is the measure of angle A in the triangle?

Enter your answer in the box.
​ m∠A= ​
°

Answer 1

m∠A = 50°

Explanation:

We know that,

The sum of the measures of the angles of a triangle is 180°.

So, we get,

`(2x-10)+(x+30)+70=180`

i.e.
`3x+20+70=180`

i.e.
`3x+90=180`

i.e.
`3x=90`

i.e. x= 30°

So, m∠A =
`(2x-10)` =
`2* 30-10` =
`60-10` = 50°

Thus, measure of angle A is 50°.

Answer 2

The interior angles of a triangle add up to 180 degrees.

(2x - 10) + (x + 30) + 70 = 180...combine like terms
3x + 90 = 180
3x = 180 - 90
3x = 90
x = 90/3
x = 30

m < A = 2x - 10 = 2(30) - 10 = 60 - 10 = 50 <== m < A