This document provides information on perfect squares, radicals, and simplifying expressions with radicals. It defines perfect squares as numbers obtained by multiplying a number by itself. It explains radicals as the square root symbol and what it represents. Examples are provided of evaluating radicals and identifying the positive and negative roots of a number. The document outlines rules for simplifying expressions with radicals, such as never leaving a perfect square or fraction under a radical sign, and rationalizing denominators that have radicals.