Answer:
<DCE = 72°
Step-by-step explanation:
If lie AB is perpendicular to each other, then the sum of angle DCE and ECB will be equivalent to 90°.
Given
<DCE = 7x+2
<ECB = x+8
Hence
<DCE + < ECB = 90
7x+2 + x+8 = 90
7x+x+2+8 = 90
8x+10 = 90
8x = 90-10
8x = 80
x = 80/8
x = 10°
Since <DCE = 7x+2, substitute x= 10 into the expression
<DCE = 7(10)+2
<DCE = 70+2
<DCE = 72°
