The document discusses the concept of area and provides formulas for calculating the area of different shapes. It defines area as the surface enclosed by a shape and explains that the area of a square is the length of one side squared. It also states that if two figures are congruent, their areas are the same, and that the area of a rectangle is calculated by multiplying its base by its height. Finally, it provides a proof that the formula for the area of a rectangle is base times height.

1. 11-1 Areas of Rectangles

7. Proof for area of a rectangle b 2 b b b h h h h h 2 b A A