I need help understanding this problem.

59

Step-by-step 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

answer rather than having to add and subtract the measurements of the semi-circle, notice that the semicircle to the left of ad is actually identical in area to the blank semicircle-shaped space to the left of bc. so if we transferred the red semicircle into the blank space, we would end up with a square of side length 24 cm. the area of a square is s^2 = 24^2 = 676 cm^2.

u also answered this so i think u would know but i am here to

put in or use mine