GED Math Formulas & Reference

Rectangle: A = length × width

Triangle: A = ½ × base × height

Circle: A = π × r² (π ≈ 3.14)

Parallelogram: A = base × height

Trapezoid: A = ½ × (b₁ + b₂) × height

Rectangle: P = 2(l + w)

Triangle: P = a + b + c

Circle: C = 2 × π × r (or π × d)

Rectangular prism: V = l × w × h

Cylinder: V = π × r² × h

Cone: V = ⅓ × π × r² × h

Sphere: V = ⁴⁄₃ × π × r³

Pyramid: V = ⅓ × base area × h

Mean: Sum of values ÷ Number of values

Median: Middle value (sorted)

Mode: Most frequent value

Range: Highest − Lowest

m = slope: (y₂ − y₁) / (x₂ − x₁)

b = y-intercept: where line crosses y-axis

Parallel lines: same slope

Perpendicular: slopes are negative reciprocals

Order of operations: PEMDAS

Absolute value: |−5| = 5

Exponents: a^m × a^n = a^(m+n)

Square root: √(a × b) = √a × √b

% = Part / Whole × 100

% change: (New − Old) / Old × 100

Cross multiply: a/b = c/d → ad = bc

Discount: Price × (1 − discount rate)

Tax: Price × (1 + tax rate)

Distributive: a(b + c) = ab + ac

FOIL: (a+b)(c+d) = ac + ad + bc + bd

Quadratic formula: x = (−b ± √(b²−4ac)) / 2a

Pythagorean theorem: a² + b² = c²