8) The circumference of a circle increases as the diameter increases, where π is the constant of proportionality. Which of these is the constant of proportionality for the length of an arc on a circle for a particular value of θ (in radians)? A) θ/2 B) θ C) π/2 D) π
θ/2 If C = πd then (θ/2π)C = (θ/2π)πd, where θ is a particular value for the central angle in radians. The arc length s = (θ/2πC) = θ/2d (this is in terms of the diameter, d/2 = r).