Area of a Circle Donut From Inner Radius and Area to Outer Radius (Closest Integer) (Level 1)

This math topic focuses on finding the outer radius of a donut-shaped figure, given its area and inner radius. This is part of introductory geometry, specifically concerning circle areas, sectors, and circular segments (often termed "donuts"). Each question provides a specific inner radius and total area, and the challenge is to determine the donut's outer radius. Options for the outer radius are given as multiple-choice answers, requiring an understanding of how to manipulate the formulas for the area of a circle to solve for the outer radius.

Work on practice problems directly here, or download the printable pdf worksheet to practice offline.

Area of a Circle Donut From Inner Radius and Area to Outer Radius (Closest Integer) Worksheet

Math worksheet on 'Area of a Circle Donut From Inner Radius and Area to Outer Radius (Closest Integer) (Level 1)'. Part of a broader unit on 'Geometry - Circle Area, Sectors and Donuts - Intro' Learn online: app.mobius.academy/math/units/geometry_circles_sector_donut_area_logic_intro/

1

Find the outer radius of the donut with an area of 150.8 and an inner radius of 4

a

4

b

9

c

8

d

2

e

5

f

13

2

Find the outer radius of the donut with an area of 37.7 and an inner radius of 2

a

1

b

4

c

2

d

5

e

3

f

13

3

Find the outer radius of the donut with an area of 75.4 and an inner radius of 1

a

2

b

3

c

10

d

5

e

4

f

8

4

Find the outer radius of the donut with an area of 21.99 and an inner radius of 3

a

8

b

5

c

10

d

9

e

1

f

4

5

Find the outer radius of the donut with an area of 172.79 and an inner radius of 3

a

1

b

15

c

2

d

17

e

5

f

8

6

Find the outer radius of the donut with an area of 100.53 and an inner radius of 7

a

18

b

4

c

9

d

1

e

3

f

14

7

Find the outer radius of the donut with an area of 141.37 and an inner radius of 2

a

7

b

1

c

16

d

2

e

14

f

15