CIRCLE:

πr²(π =constant=3.142(approx), and r = radius)

RECTANGLE:

ab (a = width and b = height of rectangle)

SQUARE:

a²(a = width = height of square, all sides equal)

TRIANGLE:

1/2(bh) (b = base width and h = height of triangle)

CYLINDER:

2π(r² + rh) ( π=constant=3.142(approx), r = radius, h = height)

CUBE:
6a² (a=length of each side of the cube)

SPHERE:
4πr² (π =constant=3.142(approx), and r = radius)

CONE:
1/3πr²h (π=constant=3.142(approx), r = radius, h = height)

RECTANGULAR PRISM:
2ab + 2ah +2bh(a = length, b = width, h= height)

CYLINDER:
πr²h (π=constant=3.142(approx), r = radius, h = height)

PYRAMID:
1/3(bh) (b = base width and h = height of pyramid)

SPHERE:
4πr²h (π=constant=3.142(approx), and r = radius)

CONE:
1/3πr²h (π=constant=3.142(approx), r = radius, h = height)

CUBE:
a³(a = length = width = height of cube, all sides equal)

CYLINDER:
πr²h (π=constant=3.142(approx), r = radius, h = height)

PYRAMID:
1/3(bh) (b = base width and h = height of pyramid)

RECTANGULAR PRISM:
abc (a = length, b = width and c = height of rectangular prism )

CIRCLE:
πd or 2πr (π=constant=3.142(approx), d = diameter and r = radius)

SQUARE:
4a or a + a + a +a (a = length of each side of square)

RECTANGLE:
2(a + b) or a + b + a + b (a = length, b = height of rectangle)