Question

The ratio of the lengths of corresponding parts in two similar solids is 21.

What is the ratio of their surface areas?
А. 2:1
В. 8:1
D. 4:1
D. 6:1

Answer 1

Option D. 4:1

Explanation:

we know that

If two solids are similar, then the ratio of the lengths of corresponding parts is equal to the scale factor and the ratio of its surface areas is equal to the scale factor squared

In this problem

The scale factor is equal to
`(2)/(1)` (ratio of corresponding lengths)

therefore

The ratio of their surface areas is equal to

`((2)/(1))^(2)=(4)/(1)`