Volume of Prisms and Cylinders The volume of

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Volume of Prisms and Cylinders

Volume of Prisms and Cylinders

The volume of a three-dimensional figure is the number of nonoverlapping unit cubes of

The volume of a three-dimensional figure is the number of nonoverlapping unit cubes of a given size that will exactly fill the interior. OR Volume is how much cubic space a figure will hold

Example 1 A: Finding Volumes of Prisms Find the volume of the prism. Round

Example 1 A: Finding Volumes of Prisms Find the volume of the prism. Round to the nearest tenth, if necessary. Volume of a right rectangular prism V = ℓwh = (13)(3)(5) Substitute 13 for ℓ, 3 for w, and 5 for h. = 195 cm 3

Example 1 B: Finding Volumes of Prisms Find the volume of a cube with

Example 1 B: Finding Volumes of Prisms Find the volume of a cube with edge length 15 in. Round to the nearest tenth, if necessary. V = s 3 = (15)3 = 3375 in 3 Volume of a cube Substitute 15 for s.

Example 2: Recreation Application A swimming pool is a rectangular prism. Estimate the volume

Example 2: Recreation Application A swimming pool is a rectangular prism. Estimate the volume of water in the pool.

Example 2 Continued Find the volume of the swimming pool in cubic feet. V

Example 2 Continued Find the volume of the swimming pool in cubic feet. V = ℓwh = (25)(19) = 3375 ft 3

Check It Out! Example 2 What if…? Estimate the volume if the height were

Check It Out! Example 2 What if…? Estimate the volume if the height were doubled. Find the volume of the aquarium in cubic feet. V = ℓwh = (120)(60)(16) = 115, 200 ft 3

Cavalieri’s principle also relates to cylinders. The two stacks have the same number of

Cavalieri’s principle also relates to cylinders. The two stacks have the same number of CDs, so they have the same volume.

Example 3 A: Finding Volumes of Cylinders Find the volume of the cylinder. Give

Example 3 A: Finding Volumes of Cylinders Find the volume of the cylinder. Give your answers in terms of and rounded to the nearest tenth. V = r 2 h Volume of a cylinder = (9)2(14) = 1134 in 3 3562. 6 in 3

Check It Out! Example 3 Find the volume of a cylinder with a diameter

Check It Out! Example 3 Find the volume of a cylinder with a diameter of 16 in. and a height of 17 in. Keep your answer in terms of . V = r 2 h Volume of a cylinder = (8)2(17) Substitute 8 for r and 17 for h. = 1088 in 3 3418. 1 in 3

Example 4: Exploring Effects of Changing Dimensions The radius and height of the cylinder

Example 4: Exploring Effects of Changing Dimensions The radius and height of the cylinder are multiplied by. Describe the effect on the volume. original dimensions: radius and height multiplied by :

Example 4 Continued The radius and height of the cylinder are multiplied by. Describe

Example 4 Continued The radius and height of the cylinder are multiplied by. Describe the effect on the volume. Notice that . If the radius and height are multiplied by by , or . , the volume is multiplied

Volume of Cones

Volume of Cones

Example: Finding Volumes of Cones Find the volume of a cone with radius 7

Example: Finding Volumes of Cones Find the volume of a cone with radius 7 cm and height 15 cm. Give your answers both in terms of and rounded to the nearest tenth. Volume of a pyramid Substitute 7 for r and 15 for h. = 245 cm 3 ≈ 769. 7 cm 3 Simplify.

Check It Out! Example 3 Find the volume of the cone. Volume of a

Check It Out! Example 3 Find the volume of the cone. Volume of a cone Substitute 9 for r and 8 for h. ≈ 216 m 3 ≈ 678. 6 m 3 Simplify.

Homework • • • Page 83, #3, 5 Page 85, #13 Page 86, #15,

Homework • • • Page 83, #3, 5 Page 85, #13 Page 86, #15, 17 Page 87, #20, 21, 26 Page 88, #29 Page 89, #37 a, 38 a