Lesson 8.3B

M.3.G.2 Apply, using appropriate units, appropriate formulas (area, perimeter, surface area, volume) to solve application problems involving polygons, prisms, pyramids, cones, cylinders, spheres as well as composite figures, expressing solutions in both exact and approximate forms

ReviewVolume: The number of cubic units needed to

fill a space

Remember, volume is always measured in units cubed

Volume of PyramidsVolume of a pyramid:

B = Area of the Base

h = height of the pyramid (not the slant height)

ExampleFind the volume of the given pyramid.

15 m

16 m

16 m

Example 2Find the volume of the given pyramid.

8.8 m

4 m

Now You Try…Find the volume of the given pyramid.

21"

10" 24"

Volume of ConesVolume of a cone: V =

r = radius of the base

h = height of the cone

ExampleFind the volume of the cone.

12 cm

10 cm

Now You Try…Find the volume of the cone.

11 in

4 in

Volume of SpheresVolume of a sphere:

r = radius of the sphere

ExampleFind the volume of the given sphere.

8cm

Word ProblemsDixie cups are cones with a 3 inch height and a

2 inch radius. How much water fits in one Dixie cup?

Example 2A spherical ice cream scoop rests on an ice cream cone that

is shaped like a right cone. Suppose the ice cream melts. Will it fit inside the cone? Justify your answer. (assume that melted and frozen ice cream have equal volume)

Now You Try…The top of the Washington Monument in Washington, D.C.,

consists of a regular square pyramid with a height of 55 ft. The length of a side of the base of the pyramid is about 34.4 ft. Find the volume.