Lesson 18 Volume of Cylinders Find the area of each circle. Use 3.14 for . 1. 2. 3. What will have more area, a square with sides that are 10 units or a circle with a diameter of 10 units? Target: Calculate the volume of cylinders. The volume of a cylinder is equal to the product of the area of the base (B) and the height (h). V = Bh V= 2 πr h Find the volume of the cylinder. Use 3.14 for π. Write the formula. Substitute known values. Find the value of the power. Multiply. V = πr2h V ≈ (3.14)(8)2(5) V ≈ (3.14)(64)(5) V ≈ 1004.8 The volume of the cylinder is about 1,004.8 cubic meters. A silo is filled with corn to the top of the cylindrical part. The cylindrical part of the silo is 90 feet tall and has a diameter of 15 feet. About how many cubic feet of corn does the silo hold? Find the length of the radius. Write the formula. Substitute known values. Find the value of the power. Multiply. Round the answer. The silo holds about 15,896 cubic feet of corn. 15 ÷ 2 = 7.5 A = πr2h A ≈ (3.14)(7.5)2(90) A ≈ (3.14)(56.25)(90) A ≈ 15,896.25 A ≈ 15,896 The volume of cylindrical water cooler is 1695.6 cubic inches. The cooler has a radius of 6 inches. Find the height of the cooler. Use 3.14 for π. Write the needed volume formula. A = πr2h Substitute known values. (1695.6) ≈ (3.14)(6)2h Find the value of the power. 1695.6 ≈ (3.14)(36)h Multiply. 1695.6 ≈ 113.04h Divide. 113.04 113.04 15 ≈ h The height of the water cooler is about 15 inches. 1. 2. Find the volume of the cylinder. Use 3.14 for . A circular swimming pool can hold 7850 cubic feet of water. The diameter of the pool is 50 feet. Find the height of the swimming pool. Use 3.14 for . You are helping out in a 2nd grade math class. The students know you are working on a unit about volume. One of the 2nd grade students asks you, “What is volume?” How would explain it to them?