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SAT Math Practice
Circles

Work with circumference, area, and radius relationships, including problems expressed in terms of π.

48 original circles questions in the SAT Ranker bank, with instant scoring and an Elo-based rank once you sign up. Below are a few free samples with full explanations.

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Sample question 1 · hard

A circle has a circumference of 90π. What is its radius?

44
✓ 45
46
90

Circumference = 2πr, so 90π = 2πr gives r = 45.

Sample question 2 · hard

A circle has a circumference of 66π. What is its radius?

✓ 33
34
66
32

Circumference = 2πr, so 66π = 2πr gives r = 33.

Sample question 3 · hard

A circle has a circumference of 38π. What is its radius?

38
18
20
✓ 19

Circumference = 2πr, so 38π = 2πr gives r = 19.

Sample question 4 · hard

A circle has a circumference of 42π. What is its radius?

22
20
✓ 21
42

Circumference = 2πr, so 42π = 2πr gives r = 21.

Sample question 5 · hard

A circle has a circumference of 74π. What is its radius?

36
74
✓ 37
38

Circumference = 2πr, so 74π = 2πr gives r = 37.

More topics
SAT Math skills
Linear Equations in One VariableLinear Equations in Two VariablesLinear FunctionsLinear InequalitiesSystems of Linear EquationsEquivalent ExpressionsNonlinear Equations and SystemsNonlinear FunctionsRatios, Rates, Proportions, and UnitsPercentagesOne-Variable DataTwo-Variable DataProbabilitySample Statistics and Margin of ErrorEvaluating Statistical ClaimsRight Triangles and TrigonometryArea and VolumeLines, Angles, and Triangles