SOLUTION: A chord 4.2cm long is 2.8cm from the centre of a circle. Calculate the radius of the circle.

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Question 1087165: A chord 4.2cm long is 2.8cm from the centre of a circle. Calculate the radius of the circle.
Answer by Alan3354(69443) About Me  (Show Source):
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A chord 4.2cm long is 2.8cm from the centre of a circle. Calculate the radius of the circle.
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2.1^2 = (r + 2.8)*(r - 2.8)
4.41 = r^2 - 7.84
r^2 = 12.25
r = 3.5
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