Wolfram Research
Wolfram Math World: Squares
MathWorld provides multiple definitions and formulas for the mathematical term, square.
Calculator Soup
Calculator Soup: Rectangle Calculator
Use this calculator if you know 2 values for the rectangle, including 1 side length, along with area, perimeter, or diagonals and you can calculate the other 3 rectangle variables. A square calculator is a special case of the rectangle...
Texas Instruments
Texas Instruments: Cross Fencing Pastures
In this activity, students use the Geoboard to determine the areas of polygons by dissecting them into parts that are squares, rectangles, and triangles.
Homeschool Math
Homeschool Math: Fraction Multiplication and Area
This fifth-grade lesson explores the area of a rectangle with fractional side lengths. We tile the rectangle with unit rectangles and show that the area is the same as would be found by multiplying the side lengths. We multiply...
Free Math Help
Free Math Help: Area Formulas
The resource consists of area formulas and diagrams for a square, rectangle, circle, triangle, and trapezoid.
Illustrative Mathematics
Illustrative Mathematics: 3.md the Square Counting Shortcut
This is a rectangle subdivision task; ideally instead of counting each square. students should break the letters into rectangles, multiply to find the areas, and add up the areas. Aligns with 3.MD.C: CCSS.Math.Content.3.MD.C.6 Measure...
ClassFlow
Class Flow: Area
[Free Registration/Login Required] This creative and engaging flipchart explains the area of all kinds of shapes, to include squares, parallelograms, rectangles, triangle, and trapezoids.
Ducksters
Ducksters: Kids Math: How to Find Surface Area
Learn how to find the surface area of various shapes square, rectangle, and triangle on this website.
Math Slice
Math Slice: Area & Perimeter: Math Worksheets
This tool allows you to create worksheets of word problems at varying levels of difficulty where students must calculate the area or perimeter of different polygon shapes. You can choose to set up the page using any of these polygon...
Khan Academy
Khan Academy: Find Perimeter by Counting Unit Squares
Calculate the perimeter of a rectangle from its side lengths. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
AAA Math
Aaa Math: Perimeter of a Square
Students are taught how to calculate the perimeter of a square. Extra practice drill problems are also included.
Annenberg Foundation
Annenberg Learner: Math in Daily Life: Home Decorating
This exhibit is designed to show students that geometry really does apply to the real world. By taking viewers through a home decoration project, students learn how to calculate area of a rectangle and circle.
National Council of Teachers of Mathematics
Nctm: Figure This: Patios
Does bigger perimeter mean bigger area? Answer this question when you try this math challenge from the NCTM Math Challenges for Families series. Discover how understanding area and perimeter can be useful in real world situations.
BBC
Bbc: Bitesize: Maths: 2 D Shapes
Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.
Calculator Soup
Calculator Soup: Parallelogram Calculator
Calculate certain variables of a parallelogram depending on the inputs provided. Calculations include side lengths, corner angles, diagonals, height, perimeter, and area of parallelograms.
ClassFlow
Class Flow: Geoboards
[Free Registration/Login Required] Geoboards bring challenge into the classroom as the student uses methods to measure length, area, and perimeters of polygons.