In three to four sentences, explain why prices decrease when a market moves from a monopoly to perfect competition.

Prices decrease because when there is a monopoly, there is normally only one business in an area so people don't have other choices, which therefore lets that business keep prices as high as they want. However, when there is other business's competing for consumer's business they must offer better deals to consumers.

S^2 = a4^2 = a4 * 4 = a16 centimeters = area of the square