Wolfram Research
Wolfram Math World: Squares
MathWorld provides multiple definitions and formulas for the mathematical term, square.
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.
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.
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...
Varsity Tutors
Varsity Tutors: Hotmath: Review: Area
Find a quick, concise explanation of area and the formulas for different shapes. An example is given to help you understand how find the area of a shape. The area formulas are listed for different types of shapes.
University of Cambridge
University of Cambridge: Nrich: Appearing Square
The challenge presented at this one-page website offers an opportunity to work with the area of a rectangle. The solution is available right on the website.
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.
Texas A&M University
Wtamu Virtual Math Lab: Intermediate Algebra
This site is a tutorial for students in algebra 2 or for those who need a refresher. The site has explanations, definitions, examples, practice problems and practice tests are found covering topics such as linear equations, graphing,...
CK-12 Foundation
Ck 12: Geometry: Unknown Dimensions Using Formulas Grade 7
[Free Registration/Login may be required to access all resource tools.] Given a perimeter or area of a figure, use formulas to solve for the unknown or missing dimensions.
Calculator Soup
Calculator Soup: Cubic Yards Calculator
Use this calculator to calculate cubic yards volume for a variety of different areas. Enter measurements in US units or metric units. Calculate volume from your measurements in inches (in), feet (ft), yards (yd), centimeters (cm), or...
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.
Math Open Reference
Math Open Reference: Quadrilaterals
A complete reference guide to quadrilaterals including squares, rectangles, parallelograms, trapezoids, and rhombus. It provides definitions and interactive activities that enhance further explanation.
Better Lesson
Better Lesson: Equivalent Numerical Expressions, Day 1 of 2
How can you represent the area of a diagram using numerical expressions? Students apply their knowledge of area and order of operations to match area diagrams with numerical expressions.
Better Lesson
Better Lesson: Equivalent Numerical Expressions, Day 2 of 2
How can you represent the area of a diagram using numerical expressions? Students connect their knowledge of area and equivalent expressions to the commutative and distributive properties for day 2 of this investigation.
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.
ClassFlow
Class Flow: Goats and Monsters
[Free Registration/Login Required] Students explore methods to measure lengths of squares and radius of a circle in trying to keep a goat from escaping.
Shodor Education Foundation
Shodor Interactivate: Perimeter Explorer
Use this applet to find the perimeter of a variety of shapes with the same or different areas.
Better Lesson
Better Lesson: Length X Width
Breaking figures into smaller squares and rectangles allows me to multiply to find the area
Mathigon
Mathigon: Geometry: Polygons and Polyhedra: Quadrilaterals
This lesson focuses on quadrilaterals which can fall into multiple categories based on the number of sides and the angles.
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.
Cuemath
Cuemath: Quadrilaterals
Explore the world of quadrilaterals and their properties. Find answers to questions like what are quadrilaterals, how they are formed, easy ways to identify them, and commonly seen quadrilaterals around us.