Coefficient of semi-circle
Pi/8
Coefficient of square
1
Isosceles right triangle (side x is a leg) coefficient
1/2
Isosceles right triangle (side x is hypotenuse) coefficient
1/4
Equilateral triangle coefficient
(Sqrt(3))/4
Rectangle
K∫(f-g)2dx or ∫h(x)(f-g)dx
Washer/disk
Pi∫(f(x))2 - (g(x))2 dx
Shell
2pi∫r(x)(f(x)-g(x))dx
Arc length
∫Sqrt(1+f’(x))dx
Surface Area
2pi∫r(x)Sqrt(1+f’(x))dx