The length of BC is (B) 12.
To get the length, we must first find the angle of the triangle using the equation tan θ = opposite/adjacent then we can derive the equation for the angle as θ =
(
). the angle (θ) = 33.69006753. Since they are similar triangles, we can use the same equation to find the length of BC. BC = tanθ*BF; BC = 
* 18 and finally we can get BC = 12.
To get the length, we must first find the angle of the triangle using the equation tan θ = opposite/adjacent then we can derive the equation for the angle as θ =