11.5 Volumes of Pyramids and Cones• The volume of a pyramid is one third the product of

the area of the base and the height of the pyramid.

1

3V Bh

Finding Volume of a Pyramid• The entrance to the Louvre Museum in Paris,

France is a square pyramid with a height of 21.64 m with sides 35.4 m. What is the approximate volume of the Louvre Pyramid?

235.4(35.4) 1253.16B m 1(1253.16)(21.64)3

V

39039.4608 9039V m

Finding the Volume of a Pyramid• What is the volume in cubic feet of a square

pyramid with base edges 40 ft and slant height 25 ft?2 2 2c a b 2 2 225 20h

2625 400h 2125 h

15h

1(40 40)(15)3

38000 ft

Volume of a Cone

• The volume of a cone is one third the product of the area of the base and the height of the cone.

21

3V r h

Finding the Volume of a Cone• The covering on a tepee rests on poles that come

together like concurrent lines. The resulting structure approximates a cone. If the tepee is 12 ft. high with a base diameter of 14 ft., what is the approximate volume?

21

3V r h

21(7) (12)

3V 615.7621601

3616 .ft

More Practice!!!!!

• Homework – Textbook p. 729 – 730 # 5 – 7, 9 – 14, 17 – 19 ALL.