Kiera's dance class starts at 4: 30 p. m. and ends at 6: 15 p. m. how long is her dance class?

Ineed to know the answer to this algebra question.

For the inequality |c| < |d| to be true, which of the following must be true?

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?