Unit 5 - Lesson 13 - Grade 8: Illustrative Mathematics

If the area of a circle is 49π square units, what is its radius? Explain your reasoning.

Figure A: A rectangular prism whose base has an area of 16 square units and whose height is 3 units.

Figure B: A cylinder whose base has an area of 16 square units and whose height is 1 unit.

Figure C: A cylinder whose base has an area of 16 square units and whose height is 3 units.

Shade the cylinder’s base.What is the area of the cylinder’s base? Express your answer in terms of π.What is the volume of this cylinder? Express your answer in terms of π.

A silo is a cylindrical container that is used on farms to hold large amounts of goods, such as grain. On a particular farm, a silo has a height of 18 feet and diameter of 6 feet. Make a sketch of this silo and label its height and radius. How many cubic feet of grain can this silo hold? Use 3.14 as an approximation for π.

What is the area of the base of the cylinder? Express your answer in terms of π.

How many cubic centimeters of fluid can fill this cylinder? Express your answer in terms of π.

Give a decimal approximation of your answer to the second question using 3.14 to approximate π.