Question

How do I do this I’ve tried so many times please help

Answer 1

100°

Explanation:

∠A and ∠B are supplementary angles, which means:

∠A° + ∠B° = 180°

`(2x) + (2x + 20) = 180`

Expand the parenthesis and solve for x:

`2x + 2x + 20 = 180`

`4x + 20 = 180`

`4x = 180 - 20`

`4x = 160`

`x = (160)/(40)`

∴
`x = 40`

Substitute the value of x to determine the measurement of ∠B:

`2(40) + 20`

`80 + 20`

= 100°