Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of...

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Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare these formulas and explain the similarity between them and the formula for the volume of a rectangular solid. Also covered: AF3.1, AF3.2 California Standards

Transcript of Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of...

Page 1: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of Cylinders

MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare these formulas and explain the similarity between them and the formula for the volume of a rectangular solid.Also covered: AF3.1, AF3.2

California Standards

Page 2: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of Cylinders

To find the volume of a cylinder, you can use the same method as you did for prisms: multiply the area of the base by the height.

V = Bh

The area of the circular base is r2.

V = r2h

Page 3: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersAdditional Example 1A: Finding the Volume of a

Cylinder

Find the volume V of the cylinder to the nearest cubic unit.

Write the formula.

Replace with 3.14, r with 4, and h with 7.Multiply.V 351.68

V = r2h

V 3.14 42 7

The volume is about 352 ft3.

Page 4: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersAdditional Example 1B: Finding the Volume of a

Cylinder

10 cm ÷ 2 = 5 cm Find the radius.

Write the formula.

Replace with 3.14, r with 5, and h with 11.Multiply.V 863.5

V = r2h

V 3.14 52 11

The volume is about 864 cm3.

Find the volume V of the cylinder to the nearest cubic unit.

Page 5: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersAdditional Example 1C: Finding the Volume of a

Cylinder

Find the radius.r = + 4h3__

r = + 4 = 793__ Substitute 9 for h.

Write the formula.

Replace with 3.14, r with 7, and h with 9.Multiply.V 1,384.74

V = r2h

V 3.14 72 9

The volume is about 1,385 in3.

Find the volume V of the cylinder to the nearest cubic unit.

Page 6: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersCheck It Out! Example 1A

Find the volume V of the cylinder to the nearest cubic unit.

Multiply.V 565.2

The volume is about 565 ft3.

6 ft

5 ft

Write the formula.

Replace with 3.14, r with 6, and h with 5.

V = r2h

V 3.14 62 5

Page 7: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersCheck It Out! Example 1B

Multiply.V 301.44

8 cm ÷ 2 = 4 cm

The volume is about 301 cm3.

Find the radius.

8 cm

6 cm

Write the formula.

Replace with 3.14, r with 4, and h with 6.

V = r2h

V 3.14 42 6

Find the volume V of the cylinder to the nearest cubic unit.

Page 8: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersCheck It Out! Example 1C

Multiply.V 1230.88

The volume is about 1,231 in3.

Find the radius.r = + 5h4__

r = + 5 = 784__ Substitute 8 for h.

r = + 5

h = 8 in.

h4

Write the formula.

Replace with 3.14, r with 7, and h with 8.

V = r2h

V 3.14 72 8

Find the volume V of the cylinder to the nearest cubic unit.

Page 9: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of Cylinders Additional Example 2A: Application Ali has a cylinder-shaped pencil holder with a 3 in. diameter and a height of 5 in. Scott has a cylinder-shaped pencil holder with a 4 in. diameter and a height of 6 in. Estimate the volume of each cylinder to the nearest cubic inch.

Ali’s pencil holder

Write the formula.

Replace with 3.14, r with 1.5, and h with 5.

Multiply.V 35.325

3 in. ÷ 2 = 1.5 in.

V 3.14 1.52 5

The volume of Ali’s pencil holder is about 35 in3.

Find the radius.

V = r2h

Page 10: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of Cylinders

Additional Example 2B: Application

Scott’s pencil holder

Write the formula.

Multiply.

4 in. ÷ 2 = 2 in.

The volume of Scott’s pencil holder is about 75 in3.

Find the radius.

V = r2h

Replace with , r with

2, and h with 6.

22 7

__V 22 622

7 __

V = 75 528 7

___ 37

__

Page 11: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersCheck It Out! Example 2A

Sara has a cylinder-shaped sunglasses case with a 3 in. diameter and a height of 6 in. Ulysses has a cylinder-shaped pencil holder with a 4 in. diameter and a height of 7 in. Estimate the volume of each cylinder to the nearest cubic inch.

Sara’s sunglasses case

Write the formula.

Replace with 3.14, r with 1.5, and h with 6.

Multiply.V 42.39

3 in. ÷ 2 = 1.5 in.

V 3.14 1.52 6

The volume of Sara’s sunglasses case is about 42 in3.

Find the radius.

V = r2h

Page 12: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of Cylinders

Check It Out! Example 2B

Ulysses’ pencil holder

Write the formula.

Multiply.

4 in. ÷ 2 = 2 in.

The volume of Ulysses’ pencil holder is about 88 in3.

Find the radius.

V = r2h

Replace with , r with

2, and h with 7.

22 7

__V 22 722

7 __

V 88

Page 13: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersAdditional Example 3: Comparing Volumes of

Cylinders Find which cylinder has the greater volume.

Cylinder 1:

V 3.14 1.52 12V = r2h

V 84.78 cm3

Cylinder 2:

V 3.14 32 6V = r2h

V 169.56 cm3

Cylinder 2 has the greater volume because 169.56 cm3 > 84.78 cm3.

Page 14: Holt CA Course 1 10-9 Volume of Cylinders MG1.3 Know and use the formulas for the volume of triangular prisms and cylinders (area of base × height); compare.

Holt CA Course 1

10-9 Volume of CylindersCheck It Out! Example 3

Find which cylinder has the greater volume.

Cylinder 1:

V 3.14 2.52 10V = r2h

V 196.25 cm3

Cylinder 2:

V 3.14 22 4V = r2h

V 50.24 cm3

Cylinder 1 has the greater volume because 196.25 cm3 > 50.24 cm3.

10 cm2.5 cm

4 cm

4 cm