1. Volume ratios of similar solids

2. If 2 similar solids have a scale factor of a:b, then,
Theorem 99-1
If 2 similar solids have a scale factor of a:b, then,
1. the ratio of the perimeters of their corresponding faces is a:b
2. the ratio of the areas of their corresponding faces is a2:b2
3. the ratio of their volumes is a3:b3

3. Corrsponding perimeters of similar solids
The scale factor is 3:2, find the perimeter of the smaller pyramid's base.
P= = 21
21 = 3 P
3P = 42
P= 14
7.5 in.
3 in.

4. Find perimeter of similar solid
Find perimeter of the larger square pyramid, if the scale factor is 4:3
7.5 cm.

5. Findins surface ares of similar solids
The surface area of the larger pyramid is 392 square cm., What is the surface area of the smaller pyramid.
142 = 392 S
14 cm.
10 cm

6. Finding surface areas of similar solids
Find the surface area of the smaller triangular prism, if the surface area of the larger is 325

7. Finding volumes of similar solids
The 2 cylinders are similar. If the volume of the smaller is 38 cubic feet, what is the volume of the larger cylinder?
33 = V
R = 3 ft
R = 2 ft

8. Finding volumes of similar prisms
2 similar prisms are shown. The volume of the larger prism is cubic cm., what is the volume of the smaller to the nearest tenth?
16 cm.
9 cm.

9. practice 2 similar triangular prisms have a scale factor of 3:4
A) find perimeter
of the larger's base
B) If surface area of
smaller is 182 sq. in.,
find the surface area of larger
C) If volume of smaller is 323 cu. In., find volume of larger
15 in.
8 in.
17 in.