square = a2
rectangle = ab
parallelogram = bh
trapezoid = h/2 (b1 + b2)
circle = pi r 2
ellipse = pi r1 r2
triangle = (1/2) b h
equilateral triangle = (1/4)(3) a2
triangle given SAS = (1/2) a b sin C
triangle given a,b,c = [s(s-a)(s-b)(s-c)] when s = (a+b+c)/2 (Heron's formula)
regular polygon = (1/2) n sin(360�/n) S2 when n = # of sides and S = length from center to a corner
VOLUMES cube = a3
rectangular prism = a b c
irregular prism = b h
cylinder = b h = r2 h
pyramid = (1/3) b h
cone = (1/3) b h = 1/3 r2 h
sphere = (4/3) r3
ellipsoid = (4/3) pi r1 r2 r3
SURFACE AREAS
cube = 6 a2
prism: (lateral area) = perimeter(b) L (total area) = perimeter(b) L + 2b
sphere = 4 r2