Question

what is the length of ac? 3 ft 4 ft 18 ft 12 ft

Explanation:

Step1: Use similar - triangles property

Since $\triangle BMN\sim\triangle BAC$ (by AA similarity), the ratios of corresponding sides are equal. $\frac{MN}{AC}=\frac{BN}{BC}$. Given $MN = 6$ ft, $BN=3$ ft, and $BC = 3 + 3=6$ ft.

Step2: Solve for $AC$

$\frac{6}{AC}=\frac{3}{6}$, cross - multiply gives $3AC = 36$, so $AC = 12$ ft.

Answer:

12 ft