Circle geometry

Use the measurements to find the circle that fits. Work out its radius, then choose from five answers.

Turn the distance between parallel walls into a radius.

6 questions · No time limit · 5 choices

Example

Example

Unscored example

Gap 12. What is the radius?

A circle touches two parallel horizontal walls, 12 units apart. Its center is on the dashed vertical guide. Find its radius. Diagram not to scale. r = ?. 12r = ?12

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Help

A tangent touches a circle at one point. Use the labeled measurements, not the apparent size of the drawing. All lengths in a question use the same unit.

Your first answer counts. Read the worked solution before moving on. Complete all six questions to save a result. Solving time excludes feedback and time spent in a hidden tab.

Later levels use the Pythagorean theorem, square roots and circle tangency.

The levels increase the size or complexity of the problems. They have not been calibrated against human performance and do not measure IQ.

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About this practice

Use the measurements to find the circle that fits. Work out its radius, then choose from five answers.

For a broader mix of practices, explore the geometry practice test. Membership is required to start a test.

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