Maricia needs new shower curtains and four bath towels. the shower curtains costs $17.99. each bath towel costs $9.99. marica has a coupon. if she spends $50 she well get $10 off. what will her total be for the shower curtain and bath towels

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?