## Basic College Mathematics (9th Edition)

A=b$\times$h is the formula for the area of a parallelogram. A=s$^2$ is the formula for the area of a square. A=$\frac{1}{2}$ $\times$h$\times$(b+B) is the formula for the area of a trapezoid. A=$\pi$$\times$r$^2$ is the formula for the area of a circle. A=l$\times$w is the formula for area of a rectangle. A=$\frac{1}{2}$ $\times$b$\times$h is the formula for the area of a triangle.