Science and Mathematics Initiative for Learning Enhancement (SMILE)
Smile: Similarity
This site contains a lesson plan for high school age learners. 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.
Texas Instruments
Texas Instruments: Circles: Circumference and Area
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.]
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.
Math Open Reference
Math Open Reference: Perimeter of a Trapezoid
Learn about the perimeter of a trapezoid with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Perimeter of a Triangle
Learn about the perimeter of a triangle with this helpful reference tool. Provides a detailed definition, an example, and an internet activity that enhances further explanation. Includes links to related topics.
Math Open Reference
Math Open Reference: Area of a Rectangle
Learn about the area of a rectangle with this helpful reference tool. Provides a detailed definition and interactive activities that enhance further explanation. Includes links to related topics.
Illustrative Mathematics
Illustrative Mathematics: 6.ee Rectangle Perimeter 3
The purpose of this task is to ask young scholars to write expressions and to consider what it means for two expressions to be equivalent. Aligns with 6.EE.A.
Alabama Learning Exchange
Alex: Geometric Quilts
Learners will use a square to investigate other polygonal shapes that can be formed. Students will work with these polygons to make designs that will later constitute cooperatively designed quilts. The quilts will be made by translating,...
Vernet -Virtual Education Resources Network
Salon Hogar: Referencia Rapida De Formulas Geometricas
This site provides the user with a useful reference to different geometric forms, their elements, formulas, and areas. Entirely in Spanish.
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...
Illustrative Mathematics
Illustrative Mathematics: 3.md Shapes and Their Insides
The purpose of this task is to help students differentiate between a polygon and the region inside of a polygon so that they understand what is being measured when the perimeter and area are being found. Aligns with 3.MD.D.
Alabama Learning Exchange
Alex: Swimming Pool Math
Young scholars will use a swimming pool example to practice finding perimeter and area of different rectangles.
University of Texas at Austin
Mathematics Teks Toolkit: Pipe Cleaners
Pipe cleaners are used to create the perimeter of a rectangle in order to explore base and height.
Illustrative Mathematics
Illustrative Mathematics: 6.g Same Base and Height, Variation 1
Make the following triangles on a geoboard. Remember that the pegs are equally spaced in a square grid. Compare the areas of the triangles. Aligns with 6.G.A.1.
BBC
Bbc: Bitesize: Maths: 2 D Shapes
Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.
ClassFlow
Class Flow: Polygon Review
[Free Registration/Login Required] This flipchart provides a review of polygons and formulas for calculating perimeter and area in the form of assessment questions.
Rice University
Rice University: Cynthia Lanius: Geometry Online
This is a site for geometry lovers. Chock-full of puzzles, games, interesting geometry facts, and online activities.
Illustrative Mathematics
Illustrative Mathematics: 6.g Base and Height
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.
Calculator Soup
Calculator Soup: Rectangle Calculator
Use this calculator if you know 2 values for the rectangle, including 1 side length, along with area, perimeter, or diagonals and you can calculate the other 3 rectangle variables. A square calculator is a special case of the rectangle...
Math Aids
Math Aids: Geometry
Great resource to practice and strengthen math skills pertaining to Geometry. Math worksheets are printable, may be customized, and include answer keys.
That Quiz
That Quiz: Practice Test: Triangles
Test your knowledge on the attributes of triangles. There are eleven levels that may be completed with or without a timer.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Medidas De Poligonos
In Spanish. Interactive activities dealing with the definition, angles and area of a polygon.
CK-12 Foundation
Ck 12: Geometry: Parallelograms
[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.
Calculator Soup
Calculator Soup: Square Calculator
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.