How can I construct interpret and describe patterns of a scatter plot

Which of the following expressions is equal to 2x^2+8

1mile equals approximately 1.6 kilometers. which best approximates the number of miles in 6 kilometers?

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?