Since the formula to find the circumference of a circle is C = dπ or C = 2πr. We know that a diameter of the circle is the same as 2 times the radius of the circle, here Sawyer and his sister are both saying the same thing, one way or the other. When Sawyer says C = d, he should multiply the d with a pi sign to get the correct circumference. Similarly when his sister says C = 2r, she is stating the congruent equation to the one of Sawyer's, therefore she needs to multiply 2r by the pi sign to get the correct circumference. Hence, both Sawyer and his sister are wrong stating the equation to solve for the circumference of the circle.
