Unit Plan
CK-12 Foundation

Ck 12: Geometry: Parallelograms

For Students 9th - 10th Standards
[Free Registration/Login may be required to access all resource tools.] This concept teaches students properties of and theorems about parallelograms and how to apply them.
Activity
CK-12 Foundation

Ck 12: Area and Perimeter of Triangles

For Students 9th - 10th Standards
[Free Registration/Login Required] Students are given the base and height of a triangle and are to determine the area and perimeter. Click challenge me to answer practice questions and click learn more to watch a video.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 6.g Same Base and Height, Variation 2

For Teachers 5th - 8th Standards
This is the second version of a task asking students to find the areas of triangles that have the same base and height. This presentation is more abstract as students are not using physical models. They still determine the area of each...
eBook
Math Planet

Math Planet: Geometry: Parallelogram, Triangles Etc

For Students 9th - 10th Standards
Resource examines the area of geometric solids through examples and a video lesson. [0:39]
Activity
Varsity Tutors

Varsity Tutors: Hotmath: Graphing Calculator Practice Problems Geometry

For Students 9th - 10th Standards
Practice using your graphing calculator for Geometry problems. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under each problem.
Activity
CK-12 Foundation

Ck 12: Area and Perimeter of Similar Polygons

For Students 5th - 7th
[Free Registration/Login Required] Students move points to make diagonals in order to solve for area and perimeter of polygons. Click challenge me to answer practice questions.
Activity
Ministry of Education and Universities of the Region of Murcia (Spain)

Ministerio De Educacion Y Ciencia: Medidas De Poligonos

For Students 9th - 10th Standards
In Spanish. Interactive activities dealing with the definition, angles and area of a polygon.
Activity
Texas Instruments

Texas Instruments: Circles: Circumference and Area

For Teachers 9th - 10th Standards
The idea of perimeter can be applied not only to polygons but to circles as well. The same idea can be said for the area of a circle. (Continued. See "before the activity.") [Requires Adobe Reader.]
eBook
Mathigon

Mathigon: Geometry: Polygons and Polyhedra: Quadrilaterals

For Students 9th - 10th Standards
This lesson focuses on quadrilaterals which can fall into multiple categories based on the number of sides and the angles.
Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: 6.g Base and Height

For Teachers 5th - 8th Standards
The purpose of this task is to help students understand what is meant by a base and its corresponding height in a triangle and to be able to correctly identify all three base-height pairs. Aligns with 6.G.A.1.
Unknown Type
That Quiz

That Quiz: Practice Test: Triangles

For Students 9th - 10th Standards
Test your knowledge on the attributes of triangles. There are eleven levels that may be completed with or without a timer.
Lesson Plan
Alabama Learning Exchange

Alex: Area and Perimeter of Various Polygons

For Teachers 9th - 10th
In this lesson students will be engaged in an interactive online practice session using area and perimeter. Students will have to use critical thinking skills in order to unlock gates and learn more about the cups in the challenge.
Website
Rice University

Rice University: Cynthia Lanius: Geometry Online

For Students 4th - 8th
This is a site for geometry lovers. Chock-full of puzzles, games, interesting geometry facts, and online activities.
Whiteboard
ClassFlow

Class Flow: Polygon Review

For Teachers 6th - 8th Standards
[Free Registration/Login Required] This flipchart provides a review of polygons and formulas for calculating perimeter and area in the form of assessment questions.
Lesson Plan
Alabama Learning Exchange

Alex: Thinking Outside the "Box"

For Teachers 6th - 8th
The middle schoolers will find the area of each two dimensional figure on a net of a rectangular prism. In groups, students will cut out the net and create a rectangular prism. Groups will then discuss how to find the lateral area and...
Lesson Plan
Science and Mathematics Initiative for Learning Enhancement (SMILE)

Smile: Similarity

For Teachers 9th - 10th Standards
This site contains a lesson plan for high school age students. The objective is to discover the factor of proportionality in similar polygons and to relate this factor to the perimeters and areas of similar polygons.
Activity
National Council of Teachers of Mathematics

Nctm: Figure This: Windshield Wipers

For Students 3rd - 8th
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...
Activity
Maths Challenge

Maths challenge.net: Inscribed Rectangle

For Students 9th - 10th Standards
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles to solve this equal area of inscribed polygons problem.
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.
Interactive
Math Playground

Math Playground: Geometry Board

For Students K - 1st Standards
Create polygons by stretching bands over pegs on this geometry board. Then find the area and perimeter of the shape you created.
Interactive
Calculator Soup

Calculator Soup: Regular Polygon Calculator

For Students 9th - 10th Standards
Use this calculator to calculate properties of a regular polygon. Enter any 1 variable plus the number of sides or the polygon name. Calculates side length, inradius, circumradius, area, and perimeter.
Whiteboard
ClassFlow

Class Flow: Geoboards

For Teachers 9th - 10th Standards
[Free Registration/Login Required] Geoboards bring challenge into the classroom as the student uses methods to measure length, area, and perimeters of polygons.
Lesson Plan
National Council of Teachers of Mathematics

The Math Forum: Suzanne Alejandre: Factor Lesson

For Teachers 9th - 10th Standards
Pupils will discover factoring through the area of a rectangle.
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.