2. Which of these sets of measurements represents the lengths of the sides of a right triangle? a. (10, 24, 26)
b. (5, 12, 24)
C. (12, 18, 30)
d. (1, 2,9)

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?