Question

A student claims that only one operation is needed to calculate the length of the subtended arc when given the measure of a central angle in radians and the diameter of the circle. Which option supports the student’s claim?

Answer 1

Having the angle in radians and the diameter of the circle we can easily calculate the length using the followingexpression

Length = angle(radians)*diameter/2

With this expression we can easily deduce the perimeter of a circle (length of the full arc)
Length = Perimeter = 2*pi*r
There is only one operation involved in this process