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
Correspondence and Transformations
Looking for a strategy to organize the information related to transformations? The materials ask pupils to identify a sequence of rigid transformations, identify corresponding angles and sides, and write a congruence statement. They...
Curated OER
Geometry - Angles Overview
Learners address 14 questions that include naming all pairs of opposite and supplementary angles for sets of intersecting lines and then, finding the measure of the unknown angle. They determine the measure of the angle that is...
EngageNY
Base Angles of Isosceles Triangles
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
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...
Willow Tree
Angles Formed by Transversals of Coplanar Lines
Create a strong understanding of the relationships formed when parallel lines intersect a transversal. Discuss each type of angle pair and their relationship to each other.
EngageNY
Similarity and the Angle Bisector Theorem
Identifying and verifying reproducible patterns in mathematics is an essential skill. Mathematicians identify the relationship of sides when an angle is bisected in a triangle. Once the pupils determine the relationship, they prove it to...
University of Utah
Geometry: Angles, Triangles, and Distance
The Pythagorean Theorem is a staple of middle school geometry. Scholars first investigate angle relationships, both in triangles and in parallel lines with a transversal, before proving and applying the Pythagorean Theorem.
EngageNY
Applications of Congruence in Terms of Rigid Motions
Corresponding parts, congruent parts, congruent corresponding parts—what does it all mean? The resource challenges pupils to identify corresponding parts for pairs of figures. It uses examples of figures that undergo rigid...
Curated OER
Similar Polygons
In this similar polygons worksheet, students identify the corresponding sides of polygons. They use proportions to solve problems. Students determine the scale factor of similar figures. This two-page worksheet contains diagrams and...
Curated OER
Exploring Congruent Triangles
In this congruent triangles worksheet, students solve 12 different equations related to writing a correspondence statement for triangles in the given diagrams. They complete each correspondence statement and write a congruence statement...
Flipped Math
Similar Figures
Use some similar problems to find side lengths. Pupils learn the definition of similar figures and how it relates to corresponding angles and sides. Using the definition, individuals calculate the lengths of missing sides and practice...
Curated OER
Corresponding Sides and Angles of Similar Triangles
Students differentiate between corresponding sides ad angles of two triangles. In this geometry lesson, students identify the differences as well as the similarities between two triangles. They differentiate between similar and...
EngageNY
Solve for Unknown Angles—Transversals
Lead your class on an exciting journey through the world of math as they review geometry facts and solve for unknown angles. They learn how to use auxiliary lines and congruent angles to correctly complete each practice problem...
Curated OER
Triangle Similarity
In this triangle similarity activity, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles shown are...
Math Mammoth
Polygons
In this polygon activity, students identify similar polygons and corresponding sides. They use a compass and ruler to construct polygons, determine the sum of the angles in a given polygon. There are 4 multi-step problems in this...
EngageNY
The Side-Angle-Side (SAS) and Side-Side-Side (SSS) Criteria for Two Triangles to Be Similar
Playing with mathematics can invoke curiosity and excitement. As pupils construct triangles with given criteria, they determine the necessary requirements to support similarity. After determining the criteria, they practice verifying...
Curated OER
Exploring Similar Figures
For this similar figures worksheet, 10th graders solve and measure 10 different angles that are similar. First, they determine which angel corresponds to each given angle. Then, students determine the scale factor of a particular...
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 angles.
Curated OER
Angles and Transversals
Pupils explore the concept of angles and transversals. They construct parallel and non-parallel lines cut by a transversal using Cabri Jr. Learners then determine which angles are congruent and the relationship of angles when two lines...
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.
Curated OER
Congruency
Which triangles are congruent? There are two sets of triangles here for scholars to examine in order to determine which of them are congruent. They use an example and explanatory introduction to guide them through this process. The first...
Curated OER
Similar Figures
In this similar figures worksheet, students identify the meaning of similar, corresponding sides, and congruent. They use proportions to find the length of a missing side. Students dilate given figures according to a scale factor. ...
Curated OER
Similar Polygons
In this similar polygons instructional activity, 10th graders solve 10 different problems that include determining various similar polygons. First, they determine the perimeter of a second triangle given the measures of all angles in the...