Pearson Geometry Common Core, 2011
PG
Pearson Geometry Common Core, 2011 View details
6. Surface Areas and Volumes of Spheres
Continue to next subchapter

Exercise 34 Page 738

Use the formula for the surface area of a sphere and the formula for the volume.

4/3Ď€m^3

Practice makes perfect

We are told that the surface area of a sphere is 4Ď€ m^2 and want to find its volume.

We first need to find its radius. To do so, we will use the formula for the surface area of a sphere. The surface area of a sphere is four times the product of π and the square of the radius. S.A.=4π r^2Let's substitute 4π for S.A. in the formula and solve for r.
S.A.=4Ď€ r^2
4Ď€=4Ď€ r^2
â–Ľ
Solve for r
1=r^2
r^2=1
r=1
The radius of a sphere with surface area 4Ď€ m^2 is 1m.
Now, let's find the volume of the sphere. The volume of a sphere is four thirds the product of π and the cube of the radius. V=4/3π r^3 Since we already know that the radius is 1, we can substitute its value for r into this formula.
V=4/3Ď€ r^3
V=4/3Ď€ ( 1)^3
V=4/3Ď€ (1)
V=4/3Ď€
The volume of a sphere in terms of π with surface area 4π m^2 is 43π m^3.