Free points and thanks if you answer first

Twelve less than a number is at most 20

What is the equation of the line that is parallel to the line with the equation y= -3/4x +1 and passes through the point (12,-12)

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?