Lesson Plan
EngageNY

#### Congruence Criteria for Triangles—SAS

For Students 9th - 10th Standards
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 if...
Instructional Video10:08
2
2
Flipped Math

#### Unit 4 Review: Triangle Congruence

For Students 9th - 12th Standards
It's time to prove one's knowledge of triangle congruence proofs. Scholars watch a video to review triangle classifications and how to use properties of triangles to set up and solve equations for missing values. They also review the...
Instructional Video11:57
2
2
Flipped Math

#### Side Splitter Theorem

For Students 9th - 12th Standards
Apply perspective to similarity. Individuals learn about the Side Splitter Theorem by looking at perspective drawings. Pupils use the theorem and its corollary to find missing lengths in figures. Next, they practice using the theorem and...
Worksheet
Mt. San Antonio Collage

#### Isosceles Triangles and Special Line Segments

For Students 9th - 12th Standards
Under which conditions can a triangle be classified as isosceles? High schoolers practice identifying isosceles triangles and special line segments, including angle bisectors, medians of triangles, and perpendicular bisectors of sides of...
Lesson Plan
Virginia Department of Education

#### Pythagorean Theorem

For Students 8th Standards
Investigate the meaning of the Pythagorean Theorem through modeling. After comparing the area of the square of each side, individuals cut triangles and squares to facilitate the comparison.
Instructional Video4:02
CK-12 Foundation

#### Classifying Parallelograms: Lesson

For Students 8th - 11th Standards
Properly organize parallelograms. Given special parallelograms, the narrator of a short video explains the properties of each. The section of a playlist on geometry uses the properties to classify the special parallelograms.
Instructional Video15:16
2
2
Flipped Math

#### SSS and SAS

For Students 9th - 12th Standards
Why use six corresponding parts when three will suffice? The second of five lessons in the Geometry - Triangle Congruence unit focuses on the SSS and SAS triangle congruence criteria. By watching a video, scholars learn how to identify...
Instructional Video13:09
2
2
Flipped Math

#### AAS and ASA

For Students 9th - 12th Standards
Sometimes one knows more about angles than about sides. Young mathematicians learn about the AAS and ASA triangle congruence criteria by watching an informative video. They use these shortcuts to demonstrate triangle congruence in...
Instructional Video10:17
2
2
Flipped Math

#### Unit 6 Review: Similar Figures

For Students 9th - 12th Standards
After a short review of the material from the Similar Figures Unit, pupils work through 18 problems to further practice the skills from the unit. Scholars apply those skills in the application problems at the end of the review.
Lesson Plan
EngageNY

#### Review of the Assumptions (part 2)

For Students 9th - 10th Standards
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...
Lesson Plan
EngageNY

#### Scale Factors

For Students 9th - 10th Standards
Is it bigger, or is it smaller—or maybe it's the same size? Individuals learn to describe enlargements and reductions and quantify the result. Lesson five in the series connects the creation of a dilated image to the result. Pupils...
Instructional Video3:58
Brightstorm

#### Triangle Angle Sum

For Students 9th - 12th Standards
Don't believe everything that you hear — make them prove it! The video shows two methods to prove the Triangle Angle Sum Theorem. The following two videos apply the theorem to finding missing angle measures.
Assessment
Mathematics Assessment Project

#### Square

For Students 8th - 12th Standards
Don't be a square! Young mathematicians determine the slope and length of a line segment. They then prove whether four given coordinate points form a square.
Lesson Plan
EngageNY

#### Looking More Carefully at Parallel Lines

For Students 9th - 10th Standards
Can you prove it? Making assumptions in geometry is commonplace. This resource requires mathematicians to prove the parallel line postulate through constructions. Learners construct parallel lines with a 180-degree rotation and then...
Lesson Plan
EngageNY

#### Angle Sum of a Triangle

For Students 8th Standards
Prove the Angle Sum Theorem of a triangle using parallel line and transversal angle relationships. Pupils create a triangle from parallel lines and transversals. They find angle measures to show that the angles of a triangle must total...
Assessment
EngageNY

For Students 8th Standards
It's time to discover what your classes have learned! The final lesson in the 25-part module is an assessment that covers the Pythagorean Theorem. Application of the theorem includes distance between points, the volume of...
Instructional Video18:51
2
2
Flipped Math

#### Conditions for Parallelograms

For Students 9th - 12th Standards
It's not a parallelogram until proven otherwise. Scholars learn about the conditions for a quadrilateral to be a parallelogram. They watch a video to see how to apply the conditions to prove that a given quadrilateral is a parallelogram.
Instructional Video17:37
2
2
Flipped Math

#### Conditions for Rectangles, Rhombuses and Squares

For Students 9th - 12th Standards
Here's a special lesson about some special parallelograms. The fifth of seven parts in the Geometry - Quadrilaterals and Polygons unit focuses on the conditions for rectangles, rhombuses, and squares. Young mathematicians use these...
Lesson Plan
Curated OER

#### Applied Maximum Minimum Problems--Mini Golf

For Teachers 12th
Twelfth graders investigate maximum and minimum as it relates to billiard and mini golf. In this calculus lesson plan, 12th graders review how to find the maximum and minimum and write proofs to show how they arrive at their answer. They...
Lesson Plan
West Contra Costa Unified School District

#### The Parallelogram Law

For Teachers 9th - 12th Standards
Use your pupils' sense of curiosity to explore the Parallelogram Law. Here is an activity that outlines a complete lesson from beginning to end, allowing pupils to follow a conjecture through to the proof stage.
Worksheet
Curated OER

#### Why do Stars Rise in the East?

For Students 8th - 10th
In this stars rise in the east worksheet, students use geometry to show how the Earth rotates from west to east and why celestial bodies appear to rise in the east and set in the west. Students draw a figure and label given points in...
Worksheet
Curated OER

#### Semester 1 Review for Geometry final

For Students 10th
In this geometry worksheet, 10th graders solve problems that are based on the topics covered in a first semester geometry class, including, linear equations and the equations of parallel and perpendicular lines, the logic of geometry,...
Instructional Video1:20
MinutePhysics

#### Proof Without Words: The Circle

For Students 9th - 12th
Showing is better than telling in a short demonstration video to find the area of a circle. The silent narrator transforms the circle, made from ball chain, into a triangle you can measure with a ruler, labeling quantities each step of...
Worksheet
Curated OER

#### Chapter 4.5 Geometry Practice Problems

For Students 10th - 11th
In this geometry practice problems worksheet, students write geometric proofs to prove the validity of given circumstances. Students prove parallel lines, perpendicular lines, and similar angles. This four-page worksheet contains eight...