Question

What is the length of AC ?

Answer 1

A. 144 is the answer

Explanation:

I took the CST

Answer 2

Triangles ABC and CDE and similar with ABC being dilated larger. This means we can use ratios to help solve for x, and then solve fo AC.


`(84)/(156-x) = (7)/(x)`

`(84x)/(156-x) = 7`

`84x = 7(156 - x)`

`84x = 1092 - 7x`

`91x = 1092`

`x = 12`
So, from this problem we now know that x is equal to 12. We merely need to plug that into what is given for AC and solve for AC.
AC = 156 - 12
AC = 144
Therefore, A is equal to 144.