A roller coaster rises 140 feet, drops 90 feet, rises
100 feet, and drops 200
feet. Describe the final
heighť of the
rollercoaster.

a. -50
b.-20
c.275
d.530

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?