This math topic focuses on understanding and calculating the area of a "circle donut". More specifically, it requires finding the outer radius of the donut, given its area and inner radius. This relates to the broader field of Geometry - Circle Area, Sectors, and Donuts. Questions present multiple choice answers for students to select from, enhancing their problem-solving skills in geometrical calculations related to circle areas.

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

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

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Area of a Circle Donut From Inner Radius and Area to Outer Radius (Equation)
1
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Find the outer radius of the donut with an area of 48 π and an inner radius of 4
a
15
b
13
c
16
d
10
e
6
f
8
2
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Find the outer radius of the donut with an area of 28 π and an inner radius of 6
a
1
b
12
c
10
d
17
e
15
f
8
3
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Find the outer radius of the donut with an area of 55 π and an inner radius of 3
a
8
b
10
c
1
d
14
e
6
f
3
4
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Find the outer radius of the donut with an area of 45 π and an inner radius of 6
a
14
b
7
c
10
d
9
e
1
f
11
5
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Find the outer radius of the donut with an area of 32 π and an inner radius of 7
a
10
b
9
c
1
d
5
e
3
f
4
6
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Find the outer radius of the donut with an area of 16 π and an inner radius of 3
a
2
b
7
c
3
d
4
e
12
f
5
7
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Find the outer radius of the donut with an area of 39 π and an inner radius of 5
a
9
b
10
c
16
d
4
e
3
f
8
8
An svg image showing a math problem
Find the outer radius of the donut with an area of 20 π and an inner radius of 4
a
9
b
12
c
1
d
6
e
10
f
4