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# What is the formula for arc length?

**2 Answers**

Two times pi times the radius multiplied by the degrees of the arc over three hundred and sixty

Arc length, s, may be found by multiplying the radius, r, by the angle, theta, of the arc. So we have s equals r times theta. If the arc goes in a complete circle, we have the circumference of a circle: s equals 2 pi r, where here theta equals 2 pi.