Which equation matches the graph of the greatest integer function given below?

What is the measure of the smallest angle in the diagram? 15 29 32 45

Use circumcenter theorem to solve for the given values

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?