Charleston School District
The Sum of Angles in a Triangle
An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the...
McGraw Hill
Triangles
After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of...
Charleston School District
Similar Triangles
Are they similar? The lesson provides an explanation of the angle-angle criterion for triangle similarity. Several problems allow the class to determine whether the two triangles with the given angle measures are similar or not.
Charleston School District
Parallel Lines Cut by a Transversal
Pupils study angle measurements between different types of angles associated with parallel lines and transversals. The independent practice asks pupils to identify the types of angles in a diagram and to determine the measure of...
Mt. San Antonio Collage
Congruent Triangles Applications
Triangles are all about threes, and practicing proving postulates is a great way to get started. The first page of the worksheet provides a brief introduction of the different properties and postulates. The remaining pages contain...
Curated OER
Trig Cheat Sheet
Your pre-calculus learners will make use of this wonderful cheat sheet that summarizes all things trigonometric. Definitions based on both the unit circle and the right triangle are included, as well as many convenient trigonometric...
Willow Tree
Angle Sum Property of Triangles
All triangles have some things in common. Using these properties of triangles, learners find missing angle measures. Scholars use the Angle Sum Property and properties of special triangles throughout the lesson.
Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate...
El Paso Community College
Geometry Definitions
Geometry is full of shapes, figures, and corresponding things here and there. The guide shares all of the key pieces of geometric information in a nicely color-coded and labeled sheet.
Centre for Innovation in Mamatics Teaching
Area, Perimeter and Volume
Develop young mathematicians' knowledge of two- and three-dimensional shapes with this geometry workbook. From learning about the classifications of different shapes and figures to calculating their area, perimeter, and volume, this...
Del Mar College
Formulas for Elementary and Intermediate Algebra
Give your scholars the support they need to work with formulas. A reference page offers definitions and picture examples of perimeter, area, surface area, volume, the Pythagorean theorem, a variety of shapes, and more.
Willow Tree
Ratios and Proportions with Congruent and Similar Polygons
Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...
West Contra Costa Unified School District
Law of Sines
One must obey the sine laws. A lesson introduces and derives the Law of Sines for non-right triangles. With examples that use the Law of Sines to determine unknown measures in triangles, the lesson checks to see if the Law...
Willow Tree
Common Geometric Figures
Geometry could be called the study of figures. An overview of the figures found in a typical geometry course contains a study of different triangles, quadrilaterals, and regular polygons.
Granite School District
7th Grade CCSS Math Vocabulary Word List
Address key vocabulary in the seventh grade Common Core Math Standards with this comprehensive list. A series of word cards is also provided that supports each term with images and examples, making this an excellent tool for teaching the...
Willow Tree
The Pythagorean Theorem
There isn't a more popular geometry formula than the Pythagorean Theorem! Learners understand the special side relationships in a right triangle. They use the Pythagorean Theorem to find missing sides and to solve problems. They begin...
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
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...
Granite School District
6th Grade CCSS Math Vocabulary Word List
Simplify the Common Core Math Standards for sixth graders with this comprehensive list of key vocabulary. Complemented by a series of word cards that support the meaning of each term with images and examples, this resource provides...
Granite School District
5th Grade CCSS Vocabulary Word List
Develop the academic language of fifth grade mathematicians with this list of Common Core vocabulary. Accompanied by a series of word cards that support each term with examples and images, this resource is a valuable tool for any fifth...
Government of Alberta
Learn alberta.ca: Mathematics Glossary: Acute Triangle
Get a visual and animated definition of what an acute triangle is, as well as examples of acute angles in the real world. [Requires Java.]
Math Open Reference
Math Open Reference: The Incenter of a Triangle
Learn about the incenter of a triangle with this handy reference guide. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
CK-12 Foundation
Ck 12: Geometry: Inequalities in Triangles Study Guide
This study guide on triangle inequalities discusses comparing angles and sides, the Triangle Inequality Theorem, and the Hinge Theorem. It is available for download with free registration.
University of Georgia
University of Georgia: Inter Math: Altitude of a Triangle
This site gives a description along with a visual representation of the altitude of a triangle. There are links to related terms, everyday examples, challenging problems, more information, and the interactive check point involving...