Question

if AB, CB, DCE = (7x + 2) and ECB = ( x + 8), find the measure of DCE. Could anyone help me? I don’t know how to solve it.

Answer 1

<DCE = 72°

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°