Interactive
Scholastic

Study Jams! Congruent Figures

For Students 4th - 7th Standards
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. 
Lesson Plan
Willow Tree

Ratios and Proportions with Congruent and Similar Polygons

For Students 8th - 11th Standards
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...
Lesson Plan
EngageNY

Congruence Criteria for Triangles—AAS and HL

For Students 9th - 10th Standards
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...
Lesson Plan
Alabama Learning Exchange

Triangle Congruence with Rigid Motion

For Students 9th - 12th Standards
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...
Unit Plan
Curated OER

Transformations in the Coordinate Plane

For Teachers 9th - 12th Standards
Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...
Unit Plan
Mathematics Vision Project

Circles: A Geometric Perspective

For Teachers 10th - 12th Standards
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Lesson Plan
EngageNY

Law of Sines

For Teachers 11th - 12th Standards
Prove the Law of Sines two ways. The ninth segment in a series of 16 introduces the Law of Sines to help the class find lengths of sides in oblique triangles. Pupils develop a proof of the Law of Sines by drawing an altitude and a second...
Worksheet
Academic Magnet High School

Parallel Lines Proofs Practice

For Students 8th - 11th Standards
Here is a worksheet that lines up perfectly with the skills needed to finish a geometric proof. Eleven problems are given to see if learners can prove that lines are parallel or angles are congruent. 
Lesson Plan
Virginia Department of Education

Inductive and Deductive Reasoning

For Teachers 9th - 11th
Introduce pupils to the two types of reasoning, inductive and deductive. Classmates work in pairs or small groups to learn the difference between the two and apply these reasonings to develop valid conclusions.