Answer:
38 = D
Explanation:
The 3 angles of a triangle equal 180 degrees
<B + <C + <D = 360
7x+ 12 + 2x+13 + 2x+ 12 =180
Combine terms
11x+37 = 180
Subtract 37 from each side
11x+37-37 = 180-37
11x =143
Divide by 11
11x/11 = 143/11
x =13
We want to find angle D
2x+12 = D
2(13) + 12 = D
26+12 = D
38 = D