Question

I need help understanding this problem.​

Answer 1

59

Explanation:

The sum of the opposite interior angles of a triangle is equal to the exterior angle

4x+11 +51 = 10x -10

Combine like terms

4x+62 = 10x -10

Subtract 4x from each side

4x+62-4x = 10x-10-4x

62 = 6x-10

Add 10 to each side

62+10 = 6x-10+10

72 = 6x

Divide by 6

72/6 = 6x/6

12 =x

We want to find angle D

<D =4x+11

= 4*12 +11

= 48+11

= 59