Ed Galaxy
Amazing Angles
Three letter-sized mini posters can be displayed in your elementary geometry class when teaching about angles. One provides information about degree measurement and additive properties, and the other two define acute, right, obtuse,...
EngageNY
Congruence Criteria for Triangles—AAS and HL
How can you prove it? Guide classes through an exploration of two possible triangle congruence criteria: AAS and HL. Learners connect this criteria to those previous learned and also explore criteria that does not work. The lesson...
EngageNY
Unknown Angle Proofs—Writing Proofs
What do Sherlock Holmes and geometry have in common? Why, it is a matter of deductive reasoning as the class learns how to justify each step of a problem. Pupils then present a known fact to ensure that their decision is correct.
Curated OER
Classifying and Measuring Angles
In this classifying and measuring angles instructional activity, 10th graders solve and complete the measures of various types of angles. They determine whether each angle drawn is a straight, right, obtuse, acute, or reflex angle. Then,...
Curated OER
What is my Angle? App
Learners estimate angle measures in this this estimating angle measures lesson. They use an application on their graphing calculator that shows various settings involving angles and then they estimate the angle measure of a clock's...
Curated OER
Geometry: Angles
In this angle worksheet, students find the value for a given variable. They use similar figures, alternate interior angles, side angle side, and other geometric theorems and proofs to determine the value of the given variable. This...
Curated OER
Geometry - Angles
In this geometry worksheet, 4th graders match 6 named angles to their characteristics. They work with right, acute, straight, reflex, obtuse, and complete rotation angles.
Curated OER
Angle Action
Young scholars measure and label specified angles. In this angles lesson, students use a protractor to find angles that are acute, obtuse, and reflexive. Young scholars then label each angle and match the angles the correct definition....
Curated OER
Angle Action 1,2 and 3
Students investigate angles through construction. In this geometry lesson, students use a protractor to identify the measurement of an angle. They identify angles cut by a transversal and two parallel lines.
Curated OER
Geometry Standardized Test Practice
In this angles and figures review worksheet, 10th graders solve and complete 39 different multiple choice problems. First, they find the length of a line between two given points. Then, students name the type of transformation and the...
Curated OER
Congruent Triangles
In this congruent triangles worksheet, 10th graders solve and complete 13 different problems. First, they use the illustrated congruent triangles to show other congruency in each problem. Then, students determine and prove the angle...
Jesuit High School
Geometry Sample Problems
I'd like to prove that this worksheet has a lot to offer. Seven problems using triangles and parallelograms practice the traditional method of a two-column proof. After the worksheet is some practice problems that show worked out...
Curated OER
Proofs
In this geometric proof worksheet, students compose 20 triangle congruency proofs. Students will decide if there is enough information in problems 1-6 to prove if any triangles are congruent. In problems 17 to 20, students use given...
EngageNY
Review of the Assumptions (part 2)
Is the amount of information getting overwhelming for your geometry classes? Use this strategy as a way to organize information. The resource provides a handout of information studied in relation to triangle congruence. It includes a...
Curated OER
Why Doesn't SSA Work?
Students investigate the relationship between angles and their sides. In this geometry lesson, students prove why SSA does not work as a true angle side relationship theorem.
EngageNY
Similarity
Learn similarity through a transformations lens! Individuals examine the effects of transformations and analyze the properties of similarity, and conclude that any image that can be created through transformations is similar. The...
Curated OER
Triangles
In this triangles instructional activity, 10th graders solve and complete 6 various types of problems. First, they draw a median and the altitude from the given angle in each triangle illustrated. Then, students determine which angle is...
Virginia Department of Education
Similar Triangles
Pupils work in pairs to investigate what it takes to prove that two triangles are similar. They work through various shortcuts to find which are enough to show a similarity relationship between the triangles. Small groups work with the...
EngageNY
Triangle Congruency Proofs (part 1)
Can they put it all together? Ninth graders apply what they know about proofs and triangle congruence to complete these proofs. These proofs go beyond the basic triangle congruence proofs and use various properties, theorems, and...
EngageNY
Triangle Congruency Proofs (part 2)
Looking to challenge your students that have mastered basic triangle congruence proofs? A collection of proofs employ previously learned definitions, theorems, and properties. Pupils draw on their past experiences with proofs to...
Curated OER
Indirect Euclidean Proofs
In this Euclidean proofs worksheet, 10th graders solve 10 different problems that include completing indirect Euclidean proofs. First, they write a statement for each of the reasons listed on the sheet of proofs. Then, students solve the...
Curated OER
Indirect Euclidean Proofs
In this indirect Euclidean proof worksheet, students write statements supporting the reasons for a given proof. This one-page worksheet contains ten problems.
Curated OER
Challenge: Skills and Applications Lesson 2.4
In this algebra activity, students create arguments using conjectures. They identify the sequence and the pattern and formula. They solve products and prove sum of integers. There are 8 questions.