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Length and Distance
Math and Arithmetic

What is the Formula for calculating chord length?


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June 18, 2008 9:19PM

Assume you mean the chord of a circle? If the angle between the two radii from the ends of the chord is A, and the radius of the circle is R, the chord length L will be

L = 2RsinA/2. You can prove this easily by joining the point bisecting the chord to the centre, you then have two rightangled triangles, with an included angle of A/2, and an opposite side of L/2. So sinA/2 = L/2R.