Answer:
c. Change the length of side CB to 8 feet
Step-by-step explanation:
If the figures are similar, the ratios should be the same
Take the side of the larger triangle over the same side of the smaller
PR PQ RQ
----------- = --------------------= ----------------
AC AB CB
7.5 5 10
----------- = --------------------= ----------------
6 4 9
7.5 /6 = 1.25
5/4 = 1.25
10/9 =1.1111(repeating)
The bases are not in the right ratio. RQ over CB = 1.25. Since RQ = 10 and the ratio is 1.25, we can solve for CB
10/CB = 1.25
Multiply by CB on each side
10 = 1.25CB
Divide by 1.25 on each side
10/1.25 = CB
8 =CB