Answer:
60
Step-by-step explanation:
<C+<D = 180 since they form a straight line
5x+20 +3x = 180
8x+20 = 180
Subtract 20 from each side
8x+20-20 = 180-20
8x = 160
Divide by 8
8x/8 = 160/8
x = 20
We want to find angle D
<D = 3x= 3*20 = 60
