AREA of a:

square

Area = side²

rectangle

Area = length x width

parallelogram

Area = base x height

triangle

Area = ½ x base x height

trapezoid

Area = ½ x (base₁ + base₂) x height

circle

Area = π x radius²; π is approximately equal to 3.14.

PERIMETER of a:

square

Perimeter = 4 x side

rectangle

Perimeter = 2 x length + 2 x width

triangle

Perimeter = side₁ + side₂ + side₃

CIRCUMFERENCE of a:

circle

Circumference = π x diameter; π is approximately equal to 3.14.

VOLUME of a:

cube

Volume = edge³

rectangular solid

Volume = length x width x height

square pyramid

Volume = 1/3(base edge)² x height

cylinder

Volume = π x radius² x height; π is approximately equal to 3.14.

cone

Volume = 1/3 x π x radius² x height

π is approximately equal to 3.14.

COORDINATE GEOMETRY

distance between points
= ;
(x₁, y₁) and (x₂, y₂) are two points in a plane.

Slope of a line = ;
(x₁, y₁) and (x₂, y₂) are two points on the line.

PYTHAGOREAN RELATIONSHIP

a² + b² = c²; a and b are legs and c the hypotenuse of a right triangle.

MEASURES OF CENTRAL TENDENCY

mean = ;
where the x's are the values for which a mean is desired, and n is the total number of values for x.

median = the middle value of an odd number of ordered scores, and halfway between the two middle values of an even number of ordered scores

SIMPLE INTEREST, DISTANCE, TOTAL COST

interest = principal x rate x time

distance = rate x time

total cost = (number of units) x (price per unit)