Finding surface area of a rectangle or square
To find the area of a rectangle or square just take the length x the height of the shape.
external image area-of-a-rectangle.gif

Finding the surface area of a triangle
To find the area of a triangle, just take length x height and then divide it by 2.
external image area-triangle-base-height.gif
Finding the surface area of a trapezoid
To find the area of a trapezoid, find the area of the inner rectangle, and the two outside triangles, then add them together.
external image c12.ht11.gif
You can find surface area of 3d shapes by finding the area of all of the shapes that make it up after you make a net, then just add them together.

Cylinder
external image 20graphicaa.gif external image cylinder.jpeg Formula: 2 π r2 + 2 π r x h

Cone
external image cone2.gifexternal image coneswrapper_web.jpg Formula:
π r2 + π r s

Sphere
4 piR squared

Square Pyramid
2 x Base x Slant Height + base squared

Rectangular Prism
2 x base x height + 2 x height(width) + 2 x base x width