Curated OER
Congruent Triangles
Students explore the concept of congruent triangles. In this congruent triangles lesson, students use Cabri Jr. to construct two congruent triangles using circles. Students determine if the two triangles are congruent by...
Alabama Learning Exchange
Triangle Congruence with Rigid Motion
Combine transformations and triangle congruence in a single lesson. Scholars learn to view congruent triangles as a rigid transformation. Using triangle congruence criteria, learners identify congruent triangles and the rigid...
EngageNY
Identical Triangles
Explore vocabulary and notation related to triangles and congruence. The fifth lesson in the 29-part series helps pupils build their knowledge of triangle relationships. Individuals identify corresponding parts of identical triangles and...
Curated OER
Mathematics Lesson for Grade 10
There are four main topics in this bundle of lesson plans. They don't need to be taught sequentially. Each lesson has three parts: a starter, a main activity, and something to help consolidate and provide reflection on concepts learned.
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 activity...
EngageNY
Congruence Criteria for Triangles—SAS
Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence...
Mathematics Vision Project
Congruence, Construction and Proof
Learn about constructing figures, proofs, and transformations. The seventh unit in a course of nine makes the connections between geometric constructions, congruence, and proofs. Scholars learn to construct special quadrilaterals,...
EngageNY
Checking for Identical Triangles II
Given a diagram of connected or overlapping triangles, individuals must find congruent parts using various properties. Pictures include reflexive sides and vertical angles amongst the marked congruent parts.
EngageNY
Using Unique Triangles to Solve Real-World and Mathematical Problems
How can congruent triangles help mark a soccer field? This is just one question your classes can answer after solving the real-world problems in the lesson plan. Each example posed through a word problem elicits higher-order thinking 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...
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...
Curated OER
Exploring Characteristics Needed to Prove Two Trianlges Congruent
Tenth graders explore congruent triangles. In this geometry lesson, 10th graders investigate the conditions necessary to prove two triangles congruent. The lesson combines dry erase board activities and the use of technology.
Curated OER
Testing For Congruent Triangles
Students define and discuss congruency and the corresponding parts between congruent triangles. They create a pair of congruent triangles, test for congruency, and complete a worksheet.
Curated OER
SuperShapes, Part 1; "Tri"ing Triangles
An outstanding lesson on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about triangle...
EngageNY
More About Similar Triangles
Determine whether two triangles are similar. The lesson presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing side...
Scholastic
Study Jams! Congruent Figures
There is more to congruency than just looking similar. Learn the difference and calculate the matching angles and sides to prove the congruence between figures. Lesson has step-by-step slides and follows with an assessment.
Corbett Maths
Constructing SAS Triangles
Two sides and an angle ... a triangle it makes. Given the measure to two sides and the angle between them, the narrator of a short video shows how to draw a triangle with a ruler and protractor. Pupils use handouts to practice the newly...
Curated OER
Hands On: Construct Triangles and Rectangles
In this congruent triangles and rectangles worksheet, students solve 6 word problems where they identify whether triangles and rectangles are congruent, and construct triangles. Students must explain their reasoning and prove each answer.
Curated OER
Corresponding Parts of Congruent Triangles
Students identify different parts of a triangle. In this geometry lesson, students differentiate between similar and congruent triangles. They use the navigator to crate a visual of the different parts of a triangle.
Curated OER
Congruent Triangles
In this geometry worksheet, 10th graders identify the corresponding parts of congruent triangles. The one page worksheet contains four problems. Answers are not provided.
EngageNY
Checking for Identical Triangles
Examine an assortment of triangle congruence criteria in a single lesson plan. Building on the four previous lessons of the series, the 13th installment provides a mixture of the different triangle congruence criteria for pupils to...
West Contra Costa Unified School District
Congruence Through Transformations
Transform your activity on transformations. Learners use given congruent triangles and tracing paper to determine the single transformation that carries one to the other. The concept is extended to combinations of transformations to...
EngageNY
Definition of Congruence and Some Basic Properties
Build a definition of congruence from an understanding of rigid transformations. The lesson asks pupils to explain congruence through a series of transformations. Properties of congruence emerge as they make comparisons to these...
EngageNY
Unique Triangles—Two Sides and a Non-Included Angle
Construct an understanding of triangle congruence through a visual analysis. Young scholars find that given two sides and a non-included angle, sometimes two possible triangles are produced. Their analysis shows that if the non-included...