Lesson 9: Practice Problems

Problem 1

A circle with a 12 inch diameter is folded in half and then folded in half again. What is the area of the resulting shape?

Problem 2

Find the area of the shaded region. Express your answer in terms of .

A shaded rectangle with three unshaded circles stacked one above the other inside the rectangle. The horizontal length of the rectangle is 18 inches. On the right side of the rectangle, the length of the vertical side is subdivied into 4 different lengths using arrows. The first arrow indicates that the distance from the top of the rectangle to the top of the first circle is 3 inches. The second arrow indicates that the distance from the top to the bottom of the first circle is 6 inches. The third arrow indicates that the distance from the top to the bottom of the second circle is 9 inches. The fourth arrow indicates that the distance between the top to the bottom of the third circle is 12 inches.

Problem 3 From Unit 3 Lesson 8

The face of a clock has a circumference of 63 in. What is the area of the face of the clock?

Problem 4 From Unit 3 Lesson 7

Are these pairs of quantities proportional to each other? For the quantities that are proportional, what is the constant of proportionality?

  1. Radius and diameter of a circle

  2. Radius and circumference of a circle

  3. Radius and area of a circle

  4. Diameter and circumference of a circle

  5. Diameter and area of a circle

Problem 5 From Unit 3 Lesson 6

Find the area of this shape in two different ways.

An irregular polygon.

Problem 6 From Unit 2 Lesson 5

Elena and Jada both read at a constant rate, but Elena reads more slowly. For every 4 pages that Elena can read, Jada can read 5.

  1. Complete the table.

    pages read
    by Elena

    pages read
    by Jada

  2. Here is an equation for the table: . What does the 1.25 mean?

  3. Write an equation for this relationship that starts