Geometric Formulas
Area

Rectangle : a = w·h
Triangle : a = (1/2)b·h
Circle : a = πr2

Perimeter

Rectangle : p = 2(w+h)
Triangle : p = a+b+c
Circle : c = 2πr  [circumference]

Surface Area

Cube : a = 6w2
Prism : a = 2w·d+2d·h+2w·h
Sphere : 4πr2
Cylinder : 2π(r2+r·h)
Cone : πr(r+r2+h2)

Volume

Cube : a = w3
Prism : a = w·d·h
Sphere : (4/3)πr3
Cylinder : πr2h
Cone : (1/3)πr2h