Curated OER
Math: Equal Area Triangles
Students examine a math worksheet and determine how to divide a single triangle into four of equal area. Using geometric principles, they sketch two additional ways to divide into into four equal triangles. To conclude, students...
Charleston School District
Review Unit 2: Congruence and Similarity
Review for the test with a comprehensive list of terms and concepts for the unit on congruence and similarity. It divides divides the sections in the order of the lessons presented during the unit.
Curated OER
Polygons All Around Us!
Pupils explore the concept of polygon properties. In this polygon properties lesson, students draw polygons with different numbers of sides such as pentagons, octagons, hexagons, etc. Pupils identify different geometric shapes in the...
Curated OER
Introduction to Fractals: Geometric Fractals
Students study and observe the patterns made by the areas of the Sierpinski Triangle. Students use the computer to draw two or three iterations to discover the number patterns. Students complete worksheets based on Geometric Fractals.
Curated OER
The Pythagorean Theorem
Seventh graders relate the Pythagorean theorem to the real world. In this algebra lesson, 7th graders identify important properties of the Pythagorean theorem and use it to solve word problems. They create a step by step plan to help...
Curated OER
CSI Investigation of Congruence and Similarity
Students differentiate between similarity and congruence using polygons. In this geometry lesson, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.
Curated OER
How Many Regular Polyhedrons Are There In This or Any Universe?
Students examine the idea of "regularity" as it pertains to geometry. For this geometry lesson students complete several assignments that are part of trihedral angles and regular polyhedrons.
Lockport City School District
Reasons for Geometric Statement/Reason Proofs
Stuck trying to remember the formal language of a geometric proof? Never fear, this handout has them all ready to go. The reasons are sectioned by topic so this handy guide is ready when you are to tackle those two column proofs.
Curated OER
What Is Hyperbolic Geometry?
Ninth graders discuss the concept of hyperbolic geometry. They complete Internet geometry activities and write essays comparing and contrasting hyperbolic geometry to Euclidean geometry.
Curated OER
Math Handbook: Trigonometry
You'll be spinning in unit circles once you read through this jumbo-sized resource of everything you need to know about trigonometry. Each page has color-coded examples with explicit directions that detail the problems and formulas.
Curated OER
Designing a Quilt Pattern
Students create and color a one-patch quilt design based upon a regular hexagon. They examine quilts and photos of quilt designs, read a handout, and complete their quilt design on a worksheet.
Curated OER
Geometric Fractals and the Chaos Game
Learners define fractals and patterns. They explore how a seemingly random process can result in a pattern. Students practice probability and fractions skills by playing the chaos game online.
Curated OER
Understanding Fundamental Trigonometric Identities
High schoolers are introduced to the basic trigonometric identities. Using a diagram, they discover why the parts of the unit circle as named as they are and use equations to finalize the Pythagorean trigonometric identities. They also...
Curated OER
Pattern Block Polygons
Sixth graders create polygons. In this shapes lesson, 6th graders explore prefixes such as oct, tri, quad, pent, etc. and share their findings. Students use pattern blocks to create two different polygons and label them.
Curated OER
The Pythagorean Theorem, the Distance Formula, and Slope
Students explore the concept of the Pythagorean Theorem. In this Pythagorean Theorem lesson, students derive the distance formula and slope of a line from the Pythagorean Theorem.
Curated OER
Areas of Polygons
Students calculate the are of regular polygons. In this geometry activity, students create polygons on the computer and move it around to create different shapes. They explore the area of different polygons and how they inter-relate.
Cuemath
Cuemath: Angle Sum Theorem
Explore the world of the angle sum theorem in this mini-lesson. Provides a definition and solved examples that help with understanding their properties. Includes practice questions with answers.
Cuemath
Cuemath: Obtuse Triangle
In this mini-lesson, learn about obtuse triangles including the obtuse triangle definition, sides, properties, examples, and other fun facts related to it.
Cuemath
Cuemath: Triangles
Explore everything about triangles. Learn about the different types, important properties, and how to find its area and perimeter. Check out the solved examples and interactive questions for better understanding.
CK-12 Foundation
Ck 12: Geometry: Triangle Relationships Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide reviews terminology for triangles, triangle properties, different types of triangles, and interior and exterior angle theorems.
Khan Academy
Khan Academy: Find Angles in Triangles
Find missing angle measures using the properties of triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
Free Math Help
Free Math Help: Exterior Angle of a Triangle
This tutorial discusses exterior angles of a triangle. Example problems with explanations are included.
Mathigon
Mathigon: Geometry: Angles and Polygons: Drawing Triangles
This lesson focuses on the Triangle Inequality, when the sum of the lengths of any two sides of a triangle is greater than the length of the third. When this happens, the three sides cannot form a triangle.
Texas Instruments
Texas Instruments: Properties of the Centers of a Triangle
Students investigate the sum of the measures of the interior angles of a triangle. This activity explores interior angles, and their relationship with the exterior angles of a triangle [Requires Adobe Reader.]