a number that has integers as its square roots
principal square root
the positive square root
the set of rational and irrational #s
square root of a negative
divide by 0 or 0 in denominator
a # that canbe written as a fraction, a # that terminates/repeats in decimal form
# that does not terminate or repeat
positive numbers without decimal ex: 0 1 2 3...
counting numbers ex: 1 2 3... (no 0!!!)
positive and negative whole numbers ex:... -3 -2 -1 0 1 2 3...
the side opposite the right angle in a right triangle
a squared + b squared = c squared