Finding Area

Area of a Rectangle

http://www.mathgoodies.com/lessons/vol1/area_rectangle.html

Area of a Parallelogram

http://www.mathgoodies.com/lessons/vol1/area_parallelogram.html

Area of a Triangle

http://www.mathgoodies.com/lessons/vol1/area_triangle.html

Area of a Trapezoid

http://www.mathgoodies.com/lessons/vol1/area_trapezoid.html