On the real GED: This formula sheet is available to you during the entire math test. You do not need to memorize these formulas — you need to know which one to use and how to plug in the numbers correctly.
Area
SquareA = s²
RectangleA = lw
ParallelogramA = bh
TriangleA = 12 bh
TrapezoidA = 12 h(b₁ + b₂)
CircleA = πr²
Perimeter
SquareP = 4s
RectangleP = 2l + 2w
TriangleP = s₁ + s₂ + s₃
Circle (circumference)C = 2πr  or  C = πd  (π ≈ 3.14)
Surface Area & Volume
Shape Surface Area Volume
Rectangular prismSA = 2lw + 2lh + 2whV = lwh
Right prismSA = ph + 2BV = Bh
CylinderSA = 2πrh + 2πr²V = πr²h
PyramidSA = 12ps + BV = 13Bh
ConeSA = πrs + πr²V = 13πr²h
SphereSA = 4πr²V = 43πr³
p = perimeter of base with area B  |  π ≈ 3.14
Data
Mean
mean is equal to the total of the values of a data set, divided by the number of elements in the data set
Median
median is the middle value in an odd number of ordered values of a data set, or the mean of the two middle values in an even number of ordered values in a data set
Algebra
Slope of a linem = y₂ − y₁x₂ − x₁
Slope-intercept formy = mx + b
Point-slope formy − y₁ = m(x − x₁)
Quadratic equationy = ax² + bx + c
Quadratic formulax = −b ± √(b²−4ac)2a
Pythagorean theorema² + b² = c²
Simple interestI = Prt
Distance formulad = rt
Total costtotal cost = units × price per unit