8 Swell Sports Copyright © 2026 Pearson Education, Inc. Swell Sports (50 – 60 minutes) Learning Objective(s): ● Students determine the effect of a dilation on the area of a circle. ● Students determine the effect of a dilation on the surface area of a sphere. ● Students determine the effect of a dilation on the volume of a sphere. Material needed: ● Student pages: Swell Sports Lesson Procedure: Warm–Up 10 minutes Prompt: What are some logos that you have seen in many places? How many different sizes of these logos have you seen? On what types of objects have you seen logos? Discuss: Marketing, logos Guided Instruction 15 minutes Present: scenario for Swell Sports. Example: A brick is a rectangular prism that is 19 cm by 9 cm by 5.7 cm. Find the area of the 19 cm by 9 cm face. 171 cm2 Find the surface area of the brick. 661.2 cm2 Find the volume of the brick. 974.7 cm3 If this brick were dilated by a factor of 2, what would the area of that side, the surface area, and volume be? 684 cm2; 2,644.8 cm2; 7,797.6 cm3 Review: key terms – dilation, area, surface area, volume dilation: a transformation that changes the size of a shape or figure area: the space a shape occupies surface area: the total area of each surface of an object volume: the amount of space an object occupies Independent Practice 20 minutes Distribute: student activity Swell Sports Allow students to work individually or in pairs. Remind students to be courteous and appropriate in their speaking and writing. Tell students to support each other as they approach the questions. Closure 10–15 minutes Review Answers: 1. a. 1,260 cm2 b. 785,000 cm2 c. 5.81 cm2 2. a. 172 cm2 b. 1,390 cm2 c. 1,810 cm2 3. a. 41.1 cm3 b. 159 cm3 c. 2.14 cm3 4. a. Multiply the original area by the square of the dilation factor. b. Multiply the original surface area by the square of the dilation factor. This is similar because they are both areas. c. Multiply the original volume by the cube of the dilation. This makes sense because the radius is cubed in the formula. Discuss: How might your answers to the questions in item 4 be different if different shapes were used?
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