A= b and c = d, then a x c = b x d what kind of reasong is used here

Which statement about the graph of y = 8(0.25)^2

What is the area of a triangle with vertices at (-3 3) (-3,2) and (1,2)?

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?