Activity
Texas Instruments

Texas Instruments: Area Formulas App

For Teachers 6th - 8th
Students review the definition and area formula for the rectangle, square, parallelogram, triangle, trapezoid, and circle.
Activity
Texas Instruments

Texas Instruments: Getting Started With Area Formulas App

For Teachers 9th - 10th Standards
Calculate the Area of a Trapezoid This Concept Handheld Software Application reviews the definition and area formula for the rectangle, square, parallelogram, triangle, trapezoid, and circle.
Unit Plan
Khan Academy

Khan Academy: Counting Unit Squares to Find Area Formula

For Students 2nd - 4th
This tutorial includes a video, questions and explanations around using unit squares to see why multiplying side-lengths can also find the area of rectangles.
Unit Plan
Free Math Help

Free Math Help: Area Formulas

For Students 9th - 10th Standards
The resource consists of area formulas and diagrams for a square, rectangle, circle, triangle, and trapezoid.
Unit Plan
Wolfram Research

Wolfram Math World: Rectangle

For Students 9th - 10th
MathWorld provides the definition of a rectangle and the area formula of a rectangle.
Unit Plan
Khan Academy

Khan Academy: Transition From Unit Squares to Area Formula

For Students 2nd - 4th Standards
Find the area of rectangles by multiplying side-lengths. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Activity
National Council of Teachers of Mathematics

The Math Forum: Seventh Grade Math: Area and Perimeter

For Students 6th - 8th
Learn how to enlarge drawings, figure out how much tile to buy to cover a specific floor, and learn about area and perimeter. These and other lesson plans are provided, including a fun interdisciplinary plan featuring dragons.
Activity
National Council of Teachers of Mathematics

The Math Forum: Find the Area of the Shape!

For Students 3rd - 8th Standards
Try to figure out the area of this challenging shape. In order to view the images, you will need to use JavaSketchpad.
Activity
BBC

Bbc: Area in General

For Students 4th - 7th Standards
You can pick up some valuable pointers on how to find the area of a triangle, rectangle, and other quadrilaterals. When you finish working your way through the pages you can take an on-line "Test Bite," and check your understanding.
Unit Plan
Varsity Tutors

Varsity Tutors: Hotmath: Review: Area

For Students 9th - 10th Standards
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.
Study Guide
Oswego City School District

Regents Exam Prep Center: Area of Polygons and Circles

For Teachers 3rd - 6th Standards
How would you find the area of a polygon or circle? Explore this concept with engaging activities at this test prep site. Here you will find detailed problem solving strategies with accompanying visuals, a reference table with formulas,...
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 6.ee Rectangle Perimeter 2

For Teachers 6th - 8th
This task is a natural follow up for task Rectangle Perimeter 1. After thinking about and using one specific expression for the perimeter of a rectangle, they now extend their thinking to equivalent expressions for the same quantity....
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 6.ee Rectangle Perimeter 1

For Teachers 5th - 8th Standards
This tasks gives a verbal description for computing the perimeter of a rectangle and asks the students to find an expression for this perimeter. They then have to use the expression to evaluate the perimeter for specific values of the...
Lesson Plan
Google

Google for Education: Area of a Circle

For Teachers 9th - 10th
Students learn to derive the formula for the area of a circle. They learn to relate a circle to a parallelogram and rectangle while learning the concept of infinity as they imagine slicing an circle into infinitesimally small slices.
Unit Plan
Mr. Martini's Classroom

Mr. Martini's Classroom: Area of Triangles, Trapezoids & Parallelograms

For Students 3rd - 8th Standards
Students solve for the area of rectangles, squares, triangles, trapezoids, and parallelograms.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Area and Perimeter of Rectangles

For Students 6th - 8th Standards
[Free Registration/Login may be required to access all resource tools.] In this lesson, students find the perimeter and area of squares and rectangles by using formulas. Students examine guided notes, review guided practice, watch...
Lesson Plan
Better Lesson

Better Lesson: Finding the Area of a Rectangle

For Teachers 6th Standards
Sixth graders use the area formula for rectangles to solve real world and mathematical problems.
Unknown Type
Khan Academy

Khan Academy: Find a Missing Side Length When Given Area of a Rectangle

For Students 3rd - 5th
In this exercise, students find a missing side length when given area of a rectangle. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Lesson Plan
Better Lesson

Better Lesson: Finding the Area Review and Assessment

For Teachers 6th Standards
Sixth graders find the area of rectangles, triangles, parallelograms, and trapezoids by using formulas or by composing into rectangles or triangles.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Unknown Dimensions Using Formulas Grade 7

For Students 7th
[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.
Activity
National Council of Teachers of Mathematics

Nctm: Illuminations: Igd: Area of a Parallelogram

For Students 3rd - 8th Standards
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.
Handout
Wolfram Research

Wolfram Math World: Area

For Students 9th - 10th Standards
Definitions and formulas for the computation of surface areas of triangles, rectangles, and any regular polygon. Helpful links to related pages.
Unit Plan
CK-12 Foundation

Ck 12: Geometry: Perimeter of Squares and Rectangles

For Students 6th
[Free Registration/Login may be required to access all resource tools.] Find the perimeter of squares and rectangles.
Activity
The Math League

The Math League: Area and Perimeter

For Students 9th - 10th Standards
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.