Jacinta is working on a jigsaw puzzle that has 403 pieces. she has completed 1/4 of the puzzle. about how many pieces has she placed in the puzzle?

, this is the last question i need for my homework!

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?