 # How do I find the surface area and volume of a sphere?

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How do I find the surface area and volume of a sphere?

6.9 Surface Area and Volume of Spheres Theorem 6.22 The surface area S of a sphere is S = _______, where r is the radius of the sphere. 4r24r2 r

6.9 Surface Area and Volume of Spheres Example 1 Find the surface area of a sphere Solution Find the surface area of the sphere. Formula for surface area of a sphere Substitute ____ for r. 7 7 cm Simplify. Use a calculator. The surface area of the sphere is about __________ square centimeters.

6.9 Surface Area and Volume of Spheres Example 2 Find the circumference of a sphere Solution The circumference of a sphere is 12  feet. Find the surface area of the sphere. Formula for circumference. Substitute ____ for C. 12  Divide each side by _____. 22 Formula for surface area Substitute ____ for r. 6 Use a calculator. The surface area of the sphere is about __________ square feet.

6.9 Surface Area and Volume of Spheres Checkpoint. Complete the following exercises. 1.The diameter of a sphere is meter. Find the surface area of the sphere.

6.9 Surface Area and Volume of Spheres Checkpoint. Complete the following exercises. 2.The circumference of a sphere is 2  inches. Find the surface area of the sphere.

6.9 Surface Area and Volume of Spheres Theorem 6.23 Volume of a Sphere The volume V of a sphere is V = _________, where r is the radius of the sphere. r

6.9 Surface Area and Volume of Spheres Example 3 Find the volume of a sphere Find the volume of the sphere. 3 mm Solution Formula for volume of a sphere Substitute ____ for r. 3 Use a calculator. The volume of the sphere is about __________ cubic millimeters.

6.9 Surface Area and Volume of Spheres Example 4 Determine the effects of a change in radius A sphere has a radius of 6 meters. The radius of a second sphere is 3 meters, which is one half the radius of the first sphere. How do the surface area and volume of the second sphere compare to the surface area and volume of the first sphere? Solution First sphere: Substitute ___ for r and simplify. Second sphere: Substitute ___ for r and simplify.

6.9 Surface Area and Volume of Spheres Example 4 Determine the effects of a change in radius A sphere has a radius of 6 meters. The radius of a second sphere is 3 meters, which is one half the radius of the first sphere. How do the surface area and volume of the second sphere compare to the surface area and volume of the first sphere? Solution The surface area of the second sphere is _______, or _____ the surface area of the first sphere. The volume of the second sphere is ________, or ____ the volume of the first sphere.

6.9 Surface Area and Volume of Spheres Checkpoint. Complete the following exercises. 3.The radius of a sphere is 2.4 centimeters. Find the volume of the sphere. Round your answer to two decimal places.

6.9 Surface Area and Volume of Spheres Checkpoint. Complete the following exercises. 4.The radius of a sphere is 4 inches. Explain how the surface area and volume changes if the radius is doubled. The surface area of the second sphere is _____ times the surface area of the first sphere. The volume of the second sphere is ____ times the volume of the first sphere.

6.9 Surface Area and Volume of Spheres Pg. 249, 6.9 #1-29

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