Activity
CK-12 Foundation

Ck 12: Perimeter of Parallelograms: Around a Trampoline

For Students 5th - 7th
[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.
Lesson Plan
Cuemath

Cuemath: Geometric Shapes

For Students 3rd - 5th Standards
In this mini-lesson, you will learn about the definition of geometric shapes and view many examples. You can check out the interactive simulations to know more about the lesson and try your hand at solving a few interesting practice...
Interactive
Calculator Soup

Calculator Soup: Rhombus Calculator

For Students 9th - 10th
Calculate certain variables of a rhombus depending on the inputs provided. Calculations include side lengths, corner angles, diagonals, height, perimeter, and area of a rhombus.
Interactive
Calculator Soup

Calculator Soup: Square Calculator

For Students 9th - 10th Standards
Use this square calculator to find the side length, diagonal length, perimeter, or area of a geometric square. Given any 1 variable you can calculate the other 3 unknowns.
Interactive
Calculator Soup

Calculator Soup: Parallelogram Calculator

For Students 9th - 10th Standards
Calculate certain variables of a parallelogram depending on the inputs provided. Calculations include side lengths, corner angles, diagonals, height, perimeter, and area of parallelograms.
Handout
The Math League

The Math League: Figures and Polygons

For Students 9th - 10th Standards
This site provides definitions of different types of polygons and figures.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 6.ee Rectangle Perimeter 3

For Teachers 5th - 8th Standards
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.
Lesson Plan
Better Lesson

Better Lesson: Differences With Shapes

For Teachers 3rd Standards
Differences between shapes are determined through measurement skills.
Activity
NumberNut

Number Nut: Shapes, Symbols, and Colors: 2 D Shapes

For Students K - 1st Standards
Did you know that two-dimensional shapes are also called polygons? This lesson describes the various 2-D shapes and includes two interactive games to reinforce skills.
Unit Plan
Khan Academy

Khan Academy: Area of Composite Shapes

For Students 5th - 7th Standards
Practice finding the areas of complex shapes that are composed of smaller shapes. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.