If equilateral polygon penta is inscribed in a circle of radius 15 inches so that all of its vertices are on the circle, what is the length of the shorter arc from vertex p to vertex n?
The shorter arc from p to n covers 2/5 of the circumference (the longer arc would cover 3/5 of it). The circumference is calculated using the formula 2*pi*r = 2*pi*(15 inches) = 30*pi inches So the length of the arc is (2/5) * (circumference) = (2/5) * (30*pi) = 12*pi inches.
