Answer: Choice D) 22.5
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Explanation:
x = length of BC
AC = AB+BC
AC = 6 + x
CE = CD+DE
CE = 22+8
CE = 30
Triangles ACE and BCD are similar triangles (can be proven by the AA similarity theorem due to the fact that AE || BD)
Therefore the corresponding sides are proportional letting us set up the proportion below
AC/BC = CE/CD
(6+x)/x = 30/22 .... substitution
22(6+x) = 30x ... cross multiply
132+22x = 30x
132 = 30x-22x ..... subtract 22x from both sides
132 = 8x
8x = 132
x = 132/8 .... divide both sides by 8
x = 16.5
Now use this to find the length of AC
AC = 6+x
AC = 6+16.5
AC = 22.5
