The Math League
The Math League: Figures and Polygons
This website has basic definitions for most polygons, regular and irregular.
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.
Texas Instruments
Texas Instruments: Investigating Area Relationships
The interactive Cabri Jr. geometry application makes it easy to measure the area of triangles and quadrilaterals. In this activity, students will explore some interesting area relationships in quadrilaterals.
Illustrative Mathematics
Illustrative Mathematics: G Srt Extensions, Bisections, Dissections in Rectangle
In this task, students must draw a diagram from a verbal description and use their understanding of similar triangles to find the area of a quadrilateral. Aligns with G-SRT.B.5.
Science Struck
Science Struck: Similarity Statement in Geometry With Examples
Models how to write a similarity statement about different types of triangles and quadrilaterals.
OER Commons
Oer Commons: Pre Assessment
Students solve for missing angle measures by applying what they have learned about types of angles and the angle measures of polygons. Students do a pre-assessment at the end of the lesson.
Geometry Help
Geometry Help: Squares
Explains the basic concept of a square with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Better Lesson
Better Lesson: Remarkable Rectangles
Rectangle is SO MUCH like triangle! Those darned angles--they'll get beginning learners! This is a fun way to practice rectangle!
ClassFlow
Class Flow: Segments and Polygons
[Free Registration/Login Required] This flipchart reviews segments, parallel and perpendicular lines and then introduces polygons including quadrilaterals. It has many real world examples of shapes and includes Activote assessment.
AAA Math
Aaa Math: Geometry
A comprehensive tutorial from AAA Math that contains explanations, interactive practices and challenging games.
Ministerio de Educacion, Cultura y Deporte (Spain)
Cnice: Relacion De Ejercicios Interactivos.
In Spanish. Interactive activities online on various geometric and trigonometric concepts such as area, perimeter, secants, tangents, etc. A terrific resource for students. Site is organized acoording to shape. (triangle, quadrilaterals,...
Wolfram Research
Wolfram Math World: Heron's Formula
This site provides a detailed overview of Heron's Formula. Content includes a definition, example, and formula.
Math Drills
Math Drills: Geometry Worksheets
Download these worksheets to sharpen your geometry skills. Sheets focus on angles, coordinate geometry, triangles, quadrilaterals, transformations, and three-dimensional geometry, and more.
ClassFlow
Class Flow: Area of Polygons
[Free Registration/Login Required] This flipchart provides students with notes and practice with using formulas for finding the area of triangles and quadrilaterals.
Math Is Fun
Math Is Fun: Interior Angles of Polygons
Learn what an interior angle of a polygon is and how you can calculate their value in triangles, quadrilaterals, and pentagons. Includes a chart that overviews the "general rule" for determining the sum of internal angles in any polygon...
Homeschool Math
Homeschool Math: Basic Shapes
This review lesson about basic shapes (polygons)contains varied hands-on exercises and tilings about triangles, quadrilaterals, pentagons, and hexagons.
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.
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.
Alabama Learning Exchange
Alex: Geometric Man
The students will explore angles, rays, line segments, perpendicular lines, parallel lines, and two-dimensional figures through the use of the book Shape Up! Fun With Triangles and Other Polygons by David A. Adler. They will also...
Better Lesson
Better Lesson: Identifying 2 D Shapes
In this activity, 2nd graders will identify shapes found around the room by recognizing their attributes such as number of angles, vertexes, and faces.
Science Struck
Science Struck: List of Different Types of Geometric Shapes
A comprehensive list of 2D shapes and 3D solids with everything from a triangle to a dodecahedron. Includes illustrations and short descriptions of attributes for each.
Ministry of Education and Universities of the Region of Murcia (Spain)
Ministerio De Educacion Y Ciencia: Teselacion Del Plano
In Spanish. Gain your knowledge of tessellation with this interactive activity. Topics include identifying regular and semi-regular tessellations and figures that will tessellate. [Requires Java.]
PBS
Pbs: Mathline: Tessellations Wow! [Pdf]
An integrated geometry instructional activity on spatial sense in which students identify and use different shapes to create a tessellation. "Through a variety of modalities such as writing, music, art, poetry, and literature, students...
OER Commons
Oer Commons: Exploring Polygons
For this lesson, middle schoolers explore different polygons by drawing them, measuring angles, and manipulating interactive sketches to find the angle sum for any polygon. Students also explore the angle measures in regular polygons....