The document discusses different formulas for calculating the area of polygons like rectangles, parallelograms, triangles, and trapezoids. It explains that the area of a rectangle can be found by multiplying its length by its width. The area of a parallelogram is the same as the original rectangle since only the shape changed, not the area. For a trapezoid, the average of the two base lengths is multiplied by the height. For a triangle, the area formula is one half the base times the height since a triangle is half of a parallelogram.