In a park, a sidewalk is built around the edge of a circular garden as shown below. The sidewalk is 5 feet wide, and the garden measures 20 feet across. Which measurement is closest to the circumference of the outer edge of the sidewalk?

A. 700ft

B. 30ft

C.75ft

D.90ft

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?