This Problem Set is a part of the Lesson 20, Unit 7, Grade 8. Students use what they know about similar triangles to determine the volume of truncated cones. Find the volume of the truncated cone. Write a proportion that will allow you to determine the height of the cone that has been removed. Explain what each part of the proportion represents. Let represent the height of the small cone. Then is the height of the large cone. The represents the base radius of the small cone, and the represents the base radius of the large cone. Solve your proportion to determine the height of the cone that has been removed.