Texas Education Agency
Texas Gateway: Area of Triangles, Parallelograms, and Trapezoids
These activities provide an opportunity for students to explore the area formulas for triangles, trapezoids, and parallelograms.
Shodor Education Foundation
Shodor Interactivate: Lesson: Area
This lesson plan helps students explore the mathematical concept of area and features resource links to further learning. CCSS.Math.Content.3.MD.C.7.a Find the area of a rectangle with whole-number side lengths by tiling it
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.
Oswego City School District
Regents Exam Prep Center: Area of Polygons and Circles
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,...
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.
Math Open Reference
Math Open Reference: Area of a Parallelogram
Learn about the area of a parallelogram with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Texas Instruments
Texas Instruments: Getting Started With Area Formulas App
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.
BBC
Bbc: Area in General
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.
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.
Quia
Ixl Learning: Area of Trapezoids
Brush up on your math skills relating to the area of trapezoids then try some practice problems to test your understanding.
CK-12 Foundation
Ck 12: Geometry: Area of a Parallelogram
[Free Registration/Login may be required to access all resource tools.] In this lesson students find the area of a parallelogram given its base and height. Students examine guided notes, review guided practice, watch instructional videos...
CK-12 Foundation
Ck 12: Geometry: Area of a Parallelogram
[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to find the area of a parallelogram. Students examine guided notes, review guided practice, watch instructional videos and attempt...
Homeschool Math
Homeschool Math: Area of Parallelograms
This lesson presents the idea that the area of any right triangle is exactly half of a certain rectangle, and contains varied exercises for students.
Khan Academy
Khan Academy: Find Missing Length When Given Area of a Parallelogram
Find the base or height of a parallelogram when given the other and the area. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Oswego City School District
Regents Exam Prep Center: Area of a Triangle and Parallelogram Using Trig
How can trigonometry be used to find the area of a triangle or parallelogram? Does the triangle need to be a right triangle, and how accurate can the results possibly be? The answers to these questions are found here along with several...
Homeschool Math
Homeschool Math: Area of Triangles
This lesson presents the idea that the area of any triangle is exactly half of a certain parallelogram -- thus we get the familiar formula of multiplying the base and the altitude and taking half of that. The lesson contains varied...
Math Open Reference
Math Open Reference: Area of a Rhombus
Learn about the area of a rhombus with this handy reference guide. Provides a detailed definition, formulas, and an interactive activity that enhances further explanation. Includes links to related topics.
Texas Education Agency
Texas Gateway: Determining Area: Composite Figures
Given information about composite fiugres, the student will determine the area of composite 2-dimensional figures comprised of a combination of triangles and parallelograms using appropriate units of measure.
Mr. Martini's Classroom
Mr. Martini's Classroom: Area of Triangles, Trapezoids & Parallelograms
Students solve for the area of rectangles, squares, triangles, trapezoids, and parallelograms.
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.
Math Planet
Math Planet: Pre Algebra: Measure Areas
Demonstrates how to calculate the area of two-dimensional shapes using formulas. Covers parallelogram, triangle, trapezoid, and circle. Includes a video modeling how to find the area of a circle and a triangle. [0:59]
CK-12 Foundation
Ck 12: Perimeter of Parallelograms: Around a Trampoline
[Free Registration/Login Required] Students move the points on the parallelogram to determine the perimeter. Click challenge me to answer practice questions and click learn more to watch a video.
Sophia Learning
Sophia: Estimating the Area of a Circle: Lesson 4
This lesson explains how triangles and parallelograms can be used to estimate the area of a circle. It is 4 of 4 in the series titled "Estimating the Area of a Circle."
Sophia Learning
Sophia: Estimating the Area of a Circle: Lesson 3
This lesson explains how triangles and parallelograms can be used to estimate the area of a circle. It is 3 of 4 in the series titled "Estimating the Area of a Circle."