what did you choose for your second piece of furniture? what are it's actual dimensions, measured to the nearest half foot? how many square lengths did you use to represent each of the dimensions​

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?