Scale: 6 cm =30m drawing length 15 cm actual length

Which of these tables represents a non-linear function?

1yd 1 ft = 1 1/12 1 1/3 1 1/2 1 1/6

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?