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.
National Council of Teachers of Mathematics
Nctm: Illuminations: Igd: Area of a Parallelogram
This applet will show you how to divide the parallelogram into pieces, arrange them together to form a rectangle, and then use the formula for the area of a rectangle to find the area of the parallelogram.
Wolfram Research
Wolfram Math World: Area
Definitions and formulas for the computation of surface areas of triangles, rectangles, and any regular polygon. Helpful links to related pages.
CK-12 Foundation
Ck 12: Geometry: Perimeter of Squares and Rectangles
[Free Registration/Login may be required to access all resource tools.] Find the perimeter of squares and rectangles.
The Math League
The Math League: Area and Perimeter
This tutorial provides a brief introduction about what area is, then gives the formulas for area of a square, rectangle, parallelogram, trapezoid, triangle, and circle. Examples of each formula are provided.
Khan Academy
Khan Academy: Find a Missing Side Length When Given Area
Practice finding a missing side length on a rectangle when given the other side length and the area. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
CK-12 Foundation
Ck 12: Geometry: Triangles and Quadrilaterals Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide reviews the formulas for area and perimeter of triangles and different kinds of quadrilaterals.
Other
Nearpod: Area & Perimeter: Rectangle
In this instructional activity on area and perimeter, 3rd graders will learn how to find the area and perimeter of rectangles by applying formulas.
Texas Instruments
Texas Instruments: Surround and Be Found! Triangular Areas, That Is!
In this activity, students use the Geoboard to determine the area of triangles using the surrounding rectangle technique. They also develop and use formulas to determine the area of triangles. [Requires Adobe Reader.]
ClassFlow
Class Flow: Area Rectangle
[Free Registration/Login Required] This flipchart will help students to solve the area for various rectangles on graph paper. It asks the students to define and solve for area using the appropriate formula.
ClassFlow
Class Flow: Area Rectangles
[Free Registration/Login Required] In this lesson students will understand area measured in square centimeters. They will understand and use the formula in words for the area of a rectangle.
Illustrative Mathematics
Illustrative Mathematics: 6.ee Rectangle Perimeter 3
The purpose of this task is to ask students to write expressions and to consider what it means for two expressions to be equivalent. Aligns with 6.EE.A.
Other
Grinnell College: Histograms Area of Rectangles
A sample problem is provided to help you create a histogram using a frequency distribution chart. Sample charts and formulas are provided to help explain how to find the area of the rectangles in the histogram and how to interpret what...
Curated OER
Rectangle
MathWorld provides the definition of a rectangle and the area formula of a rectangle.
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,...
Wolfram Research
Wolfram Math World: Squares
MathWorld provides multiple definitions and formulas for the mathematical term, square.
Alabama Learning Exchange
Alex: Pump Up the Volume
In this lesson, young scholars will be required to generate a formula for volume of a rectangular prism. Students working in cooperative groups will use prior knowledge for finding area of a rectangle to determine the "amount of area in...