Question

Find the value of X, then find AB and DC.

(opposite sides are congruent)
AB= 3x+8
DC= x+12

Answer 1

x = 2

AB = 14

DC = 14

Explanation:

If opposite sides are congruent, then:

AB = DC

AB = 3x + 8

DC = x + 12

Thus:

3x + 8 = x + 12

Collect like terms

3x - x = -8 + 12

2x = 4

Divide both sides by 2

x = 2

AB = 3x + 8

Plug in the value of x

AB = 3(2) + 8 = 14

DC = x + 12

Plug in the value of x

DC = 2 + 12 = 14