Algebra Glossary: P

parallel lines: Lines that never intersect and are always the same distance apart.

percent: Fractions with a denominator of 100. The percentage is the numerator of the fraction — how many out of 100.

perimeter: Total distance around the outside of a region or area.

permutation: Counting method that determines the number of ordered arrangements there are when a certain number of objects are selected from a given set.

perpendicular lines: Lines that form a 90-degree angle at their intersection.

pi: The letter (π) from the Greek alphabet refers to the ratio of the circumference of a circle to its diameter, which is approximately 3.14 or 22/7.

polynomial: Expression with one or more terms.

positive number: Any quantity greater than zero.

power of zero: Any number raised to the power of zero equals 1 as long as the base number isn’t zero.

prime factor: A prime number that evenly divides the number you’re working on.

prime factorization: Process of finding the prime numbers that, when multiplied together, produce a given composite number.

prime number: Whole number larger than the number 1 that can be divided evenly only by itself and 1.

principal square root: Positive number that when multiplied by itself produces a given positive number. For example, the square roots of 25 are 5 and −5, but the principal square root of 25 is only 5.

product: The result of multiplication.

proper fraction: Fraction whose value is less than 1. The numerator is always smaller than the denominator.

proportion: Equation showing that two ratios are equal to one another.

Pythagorean theorem: Formula specific to right triangles stating that the hypotenuse (c) squared is equal to the sum of the squares of the remaining sides (a and b): a2 + b2 = c2.