Rectangle

Area = length X height

Triangle

Area = (length X height) / 2

Circle

Circumference = 2π X radius OR π X diameter

Area = π (radius)2 OR 0.7854 (diameter)2

Sphere

Surface area = π (diameter)2

Cone

Surface area = (π X diameter X slope) / 2
+ area of base if solid (see circle above).

Cylinder

Surface area = π X diameter X height
+ area of ends if solid (see circle above).

Rectangular Prism

Surface area = 2(height X length) + 2(height X width) + 2(length X width)