Geometry: Two tangents to a circle form a 72° angle. What is the size of each arc between the tangent points?

From NCTM

Solution: By constructing radii from the tangent points, we have a quadrilateral, the sum of whose internal angles is 360°. The angles at the tangent points is 90°, of course, so that leaves 108° for the central angle, the same as the arc size, and the other arc is 252°.

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