Geometryhard · Past Paper
Two circles touch each other externally at point T. A direct common tangent AB touches the circles at A and B. Find the measure of angle ATB.
A45 degrees
B60 degrees
C90 degrees
D120 degrees
✓ Correct Answer: C — 90 degrees
A common tangent at T will bisect AB. In the resulting triangles, it can be proven that angle ATB = 90 degrees.
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