A. Cross multiply. 12*20 = 16x
240 = 16x (divide by 16 on both sides)
15 = x
B. Do the same as part A. just you have to make the ratio this time. x/20 = 6/8
Cross multiply. 6*20 = 8x
120 = 8x (divide by 8 on both sides)
15 = x
C. The answers to part A and B are the same because the triangles are similar.