Formula Cheat Sheet: GED Math

Updated on Apr 4, 2011

Below are mathematics formulas that you will need for the GED math.  For both sections on the GED math, a formula sheet will be provided to the test taker; however, you should be familiar and understand when and how to use the formulas prior to the test.


Square: A = side2

Rectangle: A = length × width

Parallelogram: A = base × height

Triangle: A = × base × height

Trapezoid: A = (base1 + base2) × height

Circle: A = π × radius2; π is approximately equal to 3.14.


Circle: C = π × diameter; π is approximately equal to 3.14.

Distance between Points on a Coordinate Plane

Distance between points: ; (x1,y1) and (x2,y2) are two points on the line.

Distance Formula

Distance = rate × time

Measures of Central Tendency

Mean: (x1 + x2 +… + xnx1) ÷ n, where x's are 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


Square: P = 4 × side

Rectangle: P = 2 × length + 2 × width

Triangle: P = side1 + side2 + side3

Pythagorean Theorem

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

Simple Interest Formula

Interest = principal × rate × time

Slope of a Line on a Coordinate Plane

Slope of a line: (y2y1) ÷ (x2x1); (x1, y1) and (x2, y2) are two points on the line.

Total Cost

Total cost = number of units × price per unit


Cube: V = edge3

Rectangular solid: V = length × width × height

Square pyramid: V = × (base edge)2 × height

Cone: V = × π × radius2 × height; π is approximately equal to 3.14.

Cylinder: π × radius2 × height; π is approximately equal to 3.14V = B × h (the area of the base times the height).

Rectangular solid: V = l × w × h

Cylinder: V = π × r2 × h

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