A circle has a chord of length 16 cm. If the chord is 6 cm from the centre of the circle, find the radius of the circle.
A8 cm
B10 cmCORRECT
C12 cm
D14 cm
GCEMathematicsPlane Geometry2023
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Why the answer is B, and why the others tempt you.
The perpendicular from the centre bisects the chord, creating a right-angled triangle with legs 6 cm and 8 cm (half of 16 cm). Using Pythagoras: radius² = 6² + 8² = 36 + 64 = 100, so radius = 10 cm.
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