# Math Glossary: p

 Parabola The set of points equidistance from a focus and a directrix. Parallel Means that two lines will never intersect even if they go on forever, like these: || Parallelogram A quadrilateral with both pairs of opposite sides parallel to each other. Pentagon A five-sided polygon. Percent The amount out of 100. 4/5 is equal to 80/100, and is thus 80%. Perimeter The distance around the outside of a figure. Perpendicular Lines that intersect at right angles, like in a plus sign (+). Pi The ratio of the circumference to the diameter of a circle (~3.14159). Plane Geometry The study of two-dimensional figures. Point A particular place in space that is infinitely small, and has a length, width and depth of 0. Polygon A closed figure with at least 3 straight sides, like a square or octagon. Positive Number Any integer greater than zero. {1,2,3,4,5,...} Prime Factorization The calculation of every prime factor in a given number. The prime factors of 12 are 3, 2, and 2. Prime Number An integer which can only be divided evenly by itself and 1. The smallest is 2, and others are 3,5,7,11,13,17,19... Prism A solid with parallel bases, congruent polygons, and sides that are all parallelograms. Probability The odds of an event occuring. 50% means the event will occur 1 out of every 2 times. Product The result of multiplication. In 2 x 3, 6 is the product. Proper Factor The factors of a number except itself. The proper factors of 12 are 1,2,3,4 and 6. Proper Fraction A fraction with a greater denominator than numerator, like 6/11.