O is the centre of a circle and angle AOB = 140°, where A and B are points on the circle. Find the angle in the alternate segment, that is, the angle subtended by arc AB at any point on the major arc.
A40°
B70°CORRECT
C110°
D140°
GCEMathematicsPlane Geometry2023
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Why the answer is B, and why the others tempt you.
The angle subtended by an arc at the centre is twice the angle subtended at any point on the remaining part of the circle (major arc). The angle at any point on the major arc = 140° ÷ 2 = 70°.
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