ACT Math · Circles, arcs, and sectors
Two tangent segments are drawn from an external point to a circle, forming an angle of 50° between them. What is the measure of the far…
Two tangent segments are drawn from an external point to a circle, forming an angle of 50° between them. What is the measure of the far (major) arc intercepted?
Answer and explanation
Answer: C: 230°
The angle formed by two tangents from an outside point equals half the difference of the intercepted arcs: , so far near . The two arcs make the full circle, so far near . Adding the two equations gives , so the far arc is , choice C. The near arc is , which is choice A, the minor arc rather than the far one asked for. Choice B () assumes a semicircle. Choice D () is , which wrongly equates the arc with the angle.
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