Lesson Plan
Curated OER

Similar Triangles

For Teachers 9th
Ninth graders find the height of every day objects using techniques learned through postulates that allow triangles in a problem to be similar. They calculate the length of a missing side and solve proportions.
Worksheet
Curated OER

Proportional Parts Homework

For Students 9th - 10th
In this geometry activity, learners differentiate between similarity and proportion. They use scale factor as they solve for the different proportions. There are 15 questions.
Assessment
Mathed Up!

Loci and Constructions

For Students 8th - 11th Standards
A General Certificate of Secondary Education math review has class members make basic constructions. Using a protractor and a ruler along with a compass, pupils develop drawings of triangles with given measurements. Scholars use their...
Worksheet
Curated OER

Measuring Angles

For Students 10th
In this measuring angles activity, 10th graders solve and complete 8 various types of problems. First, they use a protractor to find the measure of each angle shown. Then, students find the missing angle measures. They also refer to the...
Lesson Plan
Curated OER

Measuring Length: Practice A

For Teachers 9th
Ninth graders investigate the segment addition postulate.  In this geometry lesson, 9th graders explore the difference between equal and congruent in relation to segment length.  The lesson includes an algebra application and a...
Worksheet
Curated OER

Verifying Angle Relationships

For Students 10th
In this verifying angle relationships worksheet, 10th graders solve and prove various types of problems related to the verification process of various angle relationships. They complete each of the two proofs shown step-by-step, giving a...
Lesson Plan
Curated OER

Congruent Triangles - Is This Enough Information?

For Teachers 7th
Seventh graders examine congruence postulates and apply knowledge to triangles in the world around them.
Lesson Plan
West Contra Costa Unified School District

Investigating Similar Triangles

For Teachers 9th - 12th
Let your use of the resource be in proportion to its usefulness. Pupils investigate similar triangles by measuring side lengths and considering given angle measures. The results of the investigation help develop generalizations about...
Lesson Plan
Curated OER

Similarity and Congruence

For Teachers 9th - 12th
Learners explore the concept of similarity and congruence. In this similarity and congruence lesson, students cut out strips of paper and form a triangle. Learners try to prove that their triangles are congruent using the SSS theorem of...
Lesson Plan
Curated OER

Paragraph Proofs

For Teachers 9th - 12th
Students explore the concept of paragraph proofs. In this paragraph proofs instructional activity, students make flow charts of the process of getting ready for school. Students convert the flow chart to a paragraph proof. Students use...
Lesson Plan
Illustrative Mathematics

Do Two Points Always Determine a Linear Function?

For Teachers 9th - 12th Standards
Your learners can approach this task algebraically, geometrically, or both. They analyze the building of a linear function given two points and expand the concrete approach to the abstract when they are asked to find the general form of...
Lesson Plan
Virginia Department of Education

Logic and Conditional Statements

For Teachers 9th - 11th
If there is a conditional statement, then there is a hypothesis and conclusion. Pupils learn how to identify the parts of conditional statements. Class members continue to work with conditional statements and rewrite them in their many...
Activity
Education Development Center

Proof with Parallelogram Vertices

For Teachers 8th - 10th Standards
Geometric figures are perfect to use for proofs. Scholars prove conjectures about whether given points lie on a triangle and about midpoints. They use a provided dialogue among fictional students to frame their responses.
Lesson Plan
Curated OER

Measuring Angles & Segments

For Teachers 10th - 12th
Students view a PowerPoint for a warm-up lesson. They practice measuring around the classroom, measuring such things as the length and width of a desk, pencil, door, and book. Students use a website to practice measuring angles.
Lesson Plan
Curated OER

Congruent Trianges - Is This Enough Information?

For Teachers 7th
Seventh graders determine whether two triangles are congruent and provide an explanation to why they are not. They apply concepts of measurement of angles and collect evidence of congruent angles in the world.
Lesson Plan
Curated OER

The Truth About Triangles And Proofs

For Teachers 9th - 12th
Students engage in a lesson that is about the classification of triangles and the mathematical proofs involved in working with them. They work on a variety of problems that are created by the teacher with the focus upon the importance of...
Worksheet
Curated OER

Verifying Segment Relationships

For Students 10th
In this verifying segment relationships worksheet, 10th graders solve two proofs by following the same format used in algebra. They complete each of two proofs by naming the property that justifies each statement given. Students also...
Lesson Plan
Curated OER

Navy Sail Design

For Teachers 9th - 12th
Young scholars use the Pythagorean Theorem to explore sailboat design. In this Pythagorean Theorem lesson, two sides of a triangular sail are measured, and the theorem is used to calculate the third side. A worksheet, bulletin board...
Handout
CK-12 Foundation

Ck 12: Geometry: Basics of Geometry Study Guide

For Students 9th - 10th Standards
This study guide on Geometry covers some key vocabulary, drawing and labeling diagrams, describing geometric figures, and basic postulates for points, lines, planes, and intersections. It is available for download with free registration.
Unit Plan
Cuemath

Cuemath: Euclidean Geometry

For Students 9th - 10th Standards
Explore the world of Euclidean geometry by understanding euclidean and non-euclidean geometry, the postulates and axioms, and how to apply them while solving problems. Check-out the solved examples for better understanding and try your...
Handout
Oswego City School District

Regents Exam Prep Center: Theorems and Postulates for Geometry

For Students 9th - 10th Standards
Here is a partial list of theorems, postulates, and properties.
eBook
Mathigon

Mathigon: Euclidean Geometry: Euclid's Axioms

For Students 9th - 10th Standards
This lesson focuses on Euclid's Axioms, simple, intuitive statements, that everyone agrees are true. An axiom(or postulate) is a mathematical statement that is regarded as "self-evident" and accepted without proof. A key part of...
Lesson Plan
Rice University

Rice University: Cynthia Lanius: History of Geometry

For Students 9th - 10th Standards
Different cultures' contributions to Geometry are discussed.
Unit Plan
TED Talks

Ted: Ted Ed: Euclid's Puzzling Parallel Postulate

For Students 9th - 10th
Euclid, known as the "Father of Geometry," developed several of modern geometry's most enduring theorems--but what can we make of his mysterious fifth postulate, the parallel postulate? Jeff Dekofsky shows us how mathematical minds have...