National Council of Teachers of Mathematics
Nctm: Illuminations: Area of Triangles
To find the area of a triangle, try to make a parallelogram using a copy of the triangle.
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.
Cuemath
Cuemath: Triangles
Explore everything about triangles. Learn about the different types, important properties, and how to find its area and perimeter. Check out the solved examples and interactive questions for better understanding.
Khan Academy
Khan Academy: Area and Circumference of Parts of Circles
In this exercise, students practice find the area and circumference, of parts of circles. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.
Writing Fix
Writing Fix: Shape "Monsters" at Night
Using Melanie Watt's book entitled Scaredy Squirrel at Night, this multi-day lesson plan allows students to apply information about Scaredy Squirrel's night time experiences and its fears as their final product model. Students will...
National Council of Teachers of Mathematics
Nctm: Illuminations: Igd: Area of a Triangle
Use this interactive tool to learn how to find the area of a triangle. Click on "Instructions" for details on how to use this tool. Click on "Explore" for more ideas. [Requires Java.]
Math Open Reference
Math Open Reference: Area of a Square
A complete reference guide to finding the area of a square. It provides definitions, examples, and interactive activities that enhance further explanation. Includes links to related topics.
Illustrative Mathematics
Illustrative Mathematics: 8.g Area of a Trapezoid
Eighth graders are given various dimensions of a trapezoid and are asked to find its area. This requires them to use the Pythagorean Theorem and to decompose the trapezoid into other polygons. Aligns with 8.G.B.7.
Shodor Education Foundation
Shodor Interactivate: Triangle Explorer
This applet allows users to study the nature of triangles and their area. It draws random triangles on a Cartesian coordinate system. The user can determine the area of the triangle using his or her preferred method. After the calculated...
Math Playground
Math Playground: Geometry Board
Create polygons by stretching bands over pegs on this geometry board. Then find the area and perimeter of the shape you created.
Khan Academy
Khan Academy: Find Base and Height on a Triangle
Identify the height of a triangle when given the base. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Calculator Soup
Calculator Soup: Isosceles Triangles Calculator
Use this calculator to find the sides, perimeter, area, semiperimeter, and altitude of an isosceles triangle.
National Council of Teachers of Mathematics
Nctm: Figure This: Windshield Wipers
Test your mathematical aptitude with challenge exploring the concepts of measurement and geometry. Find the area of the windshield wipers to figure out who sees better in the rain, car drivers or truck drivers. An activity from the NCTM...
Discovery Education
Discovery Education: Web Math: Find Out Things About a Square
WebMath will calculate the side length, diagonal length, perimeter, area, or volume, given the side, perimeter, diagonal, or area. This site also displays formulas for a square.
National Council of Teachers of Mathematics
Nctm: Illuminations: Igd: Area of a Parallelogram
Use this interactive tool to learn how to find the area of a parallelogram. Click on "Instructions" for details on how to use this tool. Click on "Explore" for more ideas.
ClassFlow
Class Flow: Area of Triangles
[Free Registration/Login Required] This flipchart explores the formula for finding the area of a triangle. Examples and hints are given to help students. A video clip is included, showing how to find the height of a triangle, given the...
Illustrative Mathematics
Illustrative Mathematics: 8.g Circle Sandwich
Eighth graders are presented with a drawing of a large square inscribed by a circle which is itself inscribed by a second square. They are asked to find the area of the circle outside the smaller square and compare it to the area of the...
CK-12 Foundation
Ck 12: Unknown Dimensions of Parallelograms Grades 6 7
[Free Registration/Login may be required to access all resource tools.] Find the unknown dimensions of a parallelogram given its area and another measurement.
CK-12 Foundation
Ck 12: Unknown Dimensions of Parallelograms Grade 7
[Free Registration/Login may be required to access all resource tools.] Find unknown dimensions of parallelograms given area and one other dimension.
Illustrative Mathematics
Illustrative Mathematics: 6.rp Converting Square Units
In this task, 6th graders must inches to feet in order to find the area of a rectangular board and explain the error in the calculations made by the board owner. Aligns with 6.RP.A.3.
Khan Academy
Khan Academy: Represent Rectangle Measurements
Label the given measurements in a diagram. Find the side length of a square when given the area. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Cut the Knot
Cut the Knot!: Polygons: Formality and Intuition
This is a very interesting site about polygons. The site begins by distinguishing between shapes whose sides intersect and polygons whose sides do not overlap. After this short introduction, you will find information regarding area and...
National Council of Teachers of Mathematics
Nctm: Figure This: Keeping Cool
Is it better to by block ice or crushed ice? Use your logical reasoning and measurement skills to solve this challenge that compares surface area of block ice and the same block cut into three cubes. A one page activity from the NCTM...
CK-12 Foundation
Ck 12: Geometry: Applications of the Pythagorean Theorem
[Free Registration/Login may be required to access all resource tools.] In this lesson students use the Pythagorean Theorem to find perimeter and area. Students examine guided notes, review guided practice, watch instructional videos and...