1. Holt CA Course 1 10-9 Volume of Cylinders Warm Up Warm Up Lesson Presentation Lesson Presentation California Standards California StandardsPreview

2. Holt CA Course 1 10-9 Volume of Cylinders Warm Up Find the volume of each figure described. 359.04 cm 3 1,320 cm 3 1. rectangular prism with length 12 cm, width 11 cm, and height 10 cm 2. triangular prism with height 11 cm and triangular base with base length 10.2 cm and height 6.4 cm

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 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

4. 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 r 2. V = r 2 h

5. Holt CA Course 1 10-9 Volume of Cylinders Additional 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 = r 2 h V  3.14  4 2  7 The volume is about 352 ft 3.

6. Holt CA Course 1 10-9 Volume of Cylinders Additional Example 1B: Finding the Volume of a Cylinder 10 cm ÷ 2 = 5 cmFind the radius.Write the formula. Replace  with 3.14, r with 5, and h with 11. Multiply. V  863.5 V = r 2 h V  3.14  5 2  11 The volume is about 864 cm 3. Find the volume V of the cylinder to the nearest cubic unit.

7. Holt CA Course 1 10-9 Volume of Cylinders Additional Example 1C: Finding the Volume of a Cylinder Find the radius. r = + 4 h 3 __ r = + 4 = 7 9 3 __ Substitute 9 for h.Write the formula. Replace  with 3.14, r with 7, and h with 9. Multiply. V  1,384.74 V = r 2 h V  3.14  7 2  9 The volume is about 1,385 in 3. Find the volume V of the cylinder to the nearest cubic unit.

8. Holt CA Course 1 10-9 Volume of Cylinders Check 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 ft 3. 6 ft 5 ft Write the formula. Replace  with 3.14, r with 6, and h with 5. V = r 2 h V  3.14  6 2  5

9. Holt CA Course 1 10-9 Volume of Cylinders Check It Out! Example 1B Multiply. V  301.44 8 cm ÷ 2 = 4 cm The volume is about 301 cm 3. Find the radius. 8 cm 6 cm Write the formula. Replace  with 3.14, r with 4, and h with 6. V = r 2 h V  3.14  4 2  6 Find the volume V of the cylinder to the nearest cubic unit.

10. Holt CA Course 1 10-9 Volume of Cylinders Check It Out! Example 1C Multiply. V  1230.88 The volume is about 1,231 in 3. Find the radius. r = + 5 h 4 __ r = + 5 = 7 8 4 __ Substitute 8 for h. r = + 5 h = 8 in. h 4 Write the formula. Replace  with 3.14, r with 7, and h with 8. V = r 2 h V  3.14  7 2  8 Find the volume V of the cylinder to the nearest cubic unit.

11. 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  1.5 2  5 The volume of Ali’s pencil holder is about 35 in 3. Find the radius. V = r 2 h

12. 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 in 3. Find the radius. V = r 2 h Replace  with, r with 2, and h with 6. 22 7 __ V   2 2  6 22 7 __ V  = 75 528 7 ___ 3 7 __

13. Holt CA Course 1 10-9 Volume of Cylinders Check 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  1.5 2  6 The volume of Sara’s sunglasses case is about 42 in 3. Find the radius. V = r 2 h

14. 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 in 3. Find the radius. V = r 2 h Replace  with, r with 2, and h with 7. 22 7 __ V   2 2  7 22 7 __ V  88

15. Holt CA Course 1 10-9 Volume of Cylinders Additional Example 3: Comparing Volumes of Cylinders Find which cylinder has the greater volume. Cylinder 1: V  3.14  1.5 2  12 V = r 2 h V  84.78 cm 3 Cylinder 2: V  3.14  3 2  6 V = r 2 h V  169.56 cm 3 Cylinder 2 has the greater volume because 169.56 cm 3 > 84.78 cm 3.

16. Holt CA Course 1 10-9 Volume of Cylinders Check It Out! Example 3 Find which cylinder has the greater volume. Cylinder 1: V  3.14  2.5 2  10 V = r 2 h V  196.25 cm 3 Cylinder 2: V  3.14  2 2  4 V = r 2 h V  50.24 cm 3 Cylinder 1 has the greater volume because 196.25 cm 3 > 50.24 cm 3. 10 cm 2.5 cm 4 cm

17. Holt CA Course 1 10-9 Volume of Cylinders Lesson Quiz: Part I Find the volume of each cylinder to the nearest cubic unit. Use 3.14 as an estimate for . cylinder b ≈ 1,560.14 ft 3 193 ft 3 1,017 ft 3 ≈1,181.64 ft 3 1. radius = 9 ft, height = 4 ft 2. radius = 3.2 ft, height = 6 ft 3. Which cylinder has a greater volume? a. radius 5.6 ft and height 12 ft b. radius 9.1 ft and height 6 ft

18. Holt CA Course 1 10-9 Volume of Cylinders Lesson Quiz: Part II about 396 in 2 4. Jeff’s drum kit has two small drums. The first drum has a radius of 3 in. and a height of 14 in. The other drum has a radius of 4 in. and a height of 12 in. Estimate the volume of each cylinder to the nearest cubic inch. a. First drum b. Second drum about 603 in 2