Geometry: Theorems & Formulas

Pythagorean Theorem

a² + b² = c², where c is the hypotenuse of a right triangle

Area of a Triangle

A = ½ × base × height

Area of a Circle

A = πr²

Circumference of a Circle

C = 2πr or C = πd

Area of a Rectangle

A = length × width

Area of a Trapezoid

A = ½(b₁ + b₂) × h

Volume of a Sphere

V = (4/3)πr³

Volume of a Cylinder

V = πr²h

Volume of a Cone

V = (1/3)πr²h

Surface Area of a Sphere

SA = 4πr²