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 75.4 and an inner radius of 1

a

8

b

10

c

4

d

2

e

5

f

3

2

Find the outer radius of the donut with an area of 65.97 and an inner radius of 2

a

4

b

5

c

3

d

9

e

1

f

2

3

Find the outer radius of the donut with an area of 122.52 and an inner radius of 5

a

13

b

1

c

15

d

8

e

5

f

14

4

Find the outer radius of the donut with an area of 15.71 and an inner radius of 2

a

3

b

10

c

7

d

12

e

5

f

4

5

Find the outer radius of the donut with an area of 204.2 and an inner radius of 4

a

1

b

16

c

12

d

9

e

10

f

5

6

Find the outer radius of the donut with an area of 47.12 and an inner radius of 1

a

5

b

10

c

4

d

6

e

9

f

2

7

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

a

3

b

4

c

13

d

2

e

5

f

1