This task presents students with some creative geometric ways to represent the fraction one half. The goal is both to appeal to students' visual intuition while also providing a hands on activity to decide whether or not two areas are equal.

This resource demonstrates the distributive property through the area of rectangles. You can manipulate the dimension by moving the slider.

Ana Donevska Todorova Humboldt Universitﾊt zu Berlin Mathematisch-Naturwissenschaftliche Fakultﾊt II Institut fﾟr Mathematik, Didaktik der Mathematik

Students engage in a competitive group relay to construct formal proofs involving triangles.

New proofs can always be written to fit different curriculum and pacing.

In this course, you will study the relationships between lines and angles. You will learn to calculate how much space an object covers, determine how much space is inside of a three-dimensional object, and other relationships between shapes, objects, and the mathematics that govern them.

Geometry is concerned with the various aspects of size, shape and space. In this unit, you will explore the concepts of angles, shapes, symmetry, area and volume through interactive activities.

Students engage in a competitive group relay to construct formal proofs involving triangles.

New proofs can always be written to fit different curriculum and pacing.

In this lesson, students will how to name angles, measure and classify angles, identify congruent angles, and how to find angle measures using Angle Addition Postulate.

CK-12's Basic Geometry FlexBook is designed to present students with geometric principles in a simpler, more graphics-oriented course. Students will explore geometry at a slower pace with an emphasis placed on visual aids and approachability.

The Teacher's Edition covers tips, common errors, enrichment, differentiated instruction and problem solving for teaching CK-12's Basic Geometry Student Edition. The solution and assessment guides are available upon request.

This site teaches the Geometry of Circles to High Schoolers through a series of 1084 questions and interactive activities aligned to 9 Common Core mathematics skills.

Students engage in a competitive group relay to construct formal proofs involving triangles.

New proofs can always be written to fit different curriculum and pacing.

CK-12 Foundation's Geometry FlexBook is a clear presentation of the essentials of geometry for the high school student. Topics include: Proof, Congruent Triangles, Quadrilaterals, Similarity, Perimeter & Area, Volume, and Transformations.

This site teaches High Schoolers how to express geometric properties with equations through a series of 1721 questions and interactive activities aligned to 12 Common Core mathematics skills.

This site teaches High Schoolers Geometric Measurement and Dimension through a series of 82 questions and interactive activities aligned to 4 Common Core mathematics skills.

Consider using the information in these videos to gain student interest in geometry (4th and 5th grade) at the start of a lesson or unit. 

This geometry lesson shows that that an inscribed angle is half of a central angle that subtends the same arc. [Geometry playlist: Lesson 24 of 31]

This site teaches High Schoolers how to Interpret Categorical and Quantitative Data through a series of 45 questions and interactive activities aligned to 2 Common Core mathematics skills.

Students will use their knowledge of geometric shapes to find real world examples outdoors.

This lesson unit is intended to help teachers assess how well students are able to use geometric properties to solve problems. In particular, the lesson will help you identify and help students who have the following difficulties: solving problems by determining the lengths of the sides in right triangles; and finding the measurements of shapes by decomposing complex shapes into simpler ones. The lesson unit will also help students to recognize that there may be different approaches to geometrical problems, and to understand the relative strengths and weaknesses of those approaches.