# Lesson 9 Circling Triangles Develop Understanding

Factor.

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Circle

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Circle

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Point

Given:

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Write the equation of a circle that passes through the point

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Write the equation of a circle that passes through the point

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Let point

Draw a circle centered at the origin that passes through point

. Use the Pythagorean theorem to identify three additional points in each of the Quadrants I, II, and III that lie on the circle and do not contain the numbers and . Label the points on the circle. Write the equation of the circle.

Each arc is shown in blue.

Each indicated angle is the central angle that intercepts the given arc.

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Given:

Find

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Given:

Find

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Given:

Find

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Given:

Find

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Each radius and arc length includes a unit such as feet or meters. Explain why radian measures do not include a unit.