Question

An architect planned to construct two similar stone pyramid structures in a park. The figure below shows the front view of the pyramids in her plan, but there is an error in the dimensions:
Which of the following changes should she make to the length of side CB to correct her error?

Change the length of side CB to 13 feet
Change the length of side CB to 11 feet
Change the length of side CB to 8 feet
Change the length of side CB to 8.5 feet

Answer 1

I might be wrong, but I think the answer is C) Change the length of side CB to 8 feet. 
Hopefully that helped! :) 

Answer 2

Since the architect wants similar figures, it comes from the definition of similar triangles that the ratio of corresponding sides (all 3 sides) should be equal.

So,

$\frac{7.5}{6}= \frac{5}{4}= \frac{10}{CB}$.

Let's find CB.

$\frac{7.5}{6} =\frac{5}{4}= \frac{10}{CB}\\ 1.25=1.25=\frac{10}{CB}\\ 1.25=\frac{10}{CB}\\ 1.25CB=10\\CB=\frac{10}{1.25}\\ CB=8$

So, CB should be 8. Option C is correct.

ANSWER: Change the length of side CB to 8 feet