1. Surface areas and volumes of spheres
A sphere is a set of points in space that are a fixed distance from a given point called the center of the sphere.
A radius of a sphere is a segment whose endpoints are the center of the sphere and any point on the sphere.

2. Surface area of a sphere
The surface area of a sphere is given by the following formula, where r is the radius of the sphere
S = 4 r2

3. Calculating surface area
Find the surface area of a sphere with a radius of 8 in.
S = 4 (8)2

4. Volume of a sphere
The volume of a sphere is given by the following formula, where r is the radius of the sphere
V = 4/3 r3

5. Calculate volume of a sphere
Find the volume of a sphere with radius 16 m.
V = 4/3 (16)3

6. Hemisphere A hemisphere is half of a sphere.
A great circle is a circle on a sphere that divides the sphere into 2 hemispheres.
An example of a hemisphere is the equator since it divides the Earth into 2 congruent hemispheres

7. Volume of a hemisphere
Volume of a hemisphere is equal to half the volume of the sphere with the same radius V = 1/2 (4/3 r3)
Surface area of a hemisphere is the half the surface area of the sphere plus the area of the great circle
SA = 1/2 (4 r2) + r2

8. Calculating Surface area and volume of a hemisphere
Find the surface area and volume of a hemisphere with an 18-foot diameter.

9. Practice
1. Find the surface area of a sphere with an 8-meter diameter to the nearest hundredth of a square meter.
2. Find the volume of a sphere with a diameter of 22 in., to the nearest hundredth of a cubic inch.
3.Find the surface area and volume of a hemisphere with a 16-foot radius to the nearest hundredth of a foot.
4. A snowglobe's circumference is 20 cm. How much water does it take to fill the globe, to the nearest hundredth of a cubic cm.