Find the slope of the line

Answer this 30 points and brainliest!

Bradley hikes 12 miles in 3 hours. in relation to bradley’s hike, which statement describes the expression

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?