
Areassquare = a^{2}rectangle = ab circle = p r^{2} ellipse = p r1 r2 triangle = (1/2) b h equilateral triangle = Ö3/4 a^{2} triangle given SAS = (1/2) a b sin C triangle given a,b,c = Ö[s(sa)(sb)(sc)] when s = (a+b+c)/2 (Heron's formula) parallelogram = bh trapezoid = h/2 (b1 + b2) regular polygon = (1/2) n sin(360°/n) a^{2} when n = # of sides and a = length from center to a corner Volumescube = a^{3}rectangular prism = a b c irregular prism = b h cylinder = b h = p r^{2}h pyramid = (1/3) b h cone = (1/3) b h = 1/3 [p r^{2} h ] sphere = (4/3) p r^{3} ellipsoid = (4/3) p r1 r2 r3 Directions: Memorize the above formulae and have someone test your knowledge. Write all the formulas on a sheet of paper. 