87.5k views
5 votes
These cones are similar. Find the surface

area of the smaller cone. Round to the
nearest tenth.
2 cm
3 cm
Surface Area = [ ? ) cm2 Surface Area = 75 cm2
Helppppp plssss

These cones are similar. Find the surface area of the smaller cone. Round to the nearest-example-1
User Arocketman
by
4.1k points

1 Answer

1 vote

Answer:

33.3 cm²

Explanation:

Recall: Area Scale Factor = (Linear Scale Factor)²

Area scale factor = surface area of bigger cone/surface area of smaller cone

Let the surface area of the smaller cone be represented as x

Therefore,

Area scale factor = 75/x

Linear scale factor = radius of bigger cone/radius of smaller cone = 3/2

Thus:

75/x = (3/2)²

75/x = 9/4

Cross multiply

x*9 = 75*4

9x = 300

Divide both sides by 9

x = 300/9

x = 33.3 cm² (nearest tenth)

User Qwertz
by
3.3k points