This website will help you with squares and their properties. Such as side length, diagonal length, area and perimeter.
WebMath

This page gives two methods for finding the area of a kite: a geometry formula and a trigonometric formula. Numerous connected pages offer a wide variety of information on all types of polygons.
Math Open Reference

A quick reference of area formulas.
SolveMyMath.com Area Formulas

A helpful scientific calculator that runs in your web browser window.
Holt Online Learning

Worksheet to practice calculating surface area for rectangular prisms.
Helping with Math

Worksheet to practice using the formula for the area of a circle.
Helping with Math

A page with links for properties of circles and different types of polygons. Each link has great visuals with clear markings, definitions, and formulas.
Cool Math

Comprehensive list of formulas for finding the area, volume and surface area of various shapes.
Math2

Formulas with corresponding pictures, help tutors and student review all the area fomula of plane shapes
Math is fun

This geometry help reference sheet contains the circumference and area formulas for the following shapes: square, rectangle, circle, triangle, parallelogram, and trapezoid. It also includes the area of a circular ring as well as the area and segment length of a circular sector. This reference sheet contains formulas for area and volume of rectangular box, cube, and cylinder. This math help sheet also includes the area, side length, and volume of a right circular cone, as well as the volume of a frustum of a cone.
eCalc.com
