greg bought a blanket for $33.34, a flag for $12.25, and a glove for $12.75. He paid $40 and the rest he borrowed from his friend. If greg got $1.66 in change, how much did he borrow from his friend to pay for all the items?

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?