Lesson Plan
Curated OER

Investigating Trigonometric Ratios Through Similar Right Triangles.

For Teachers 8th - 10th
49Students investigate the properties of right triangles. In this geometry lesson, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.
Interactive
Curated OER

Self-Check for Triangle Congruence Proofs Multiple Choice

For Students 8th - 10th
In this triangle congruence worksheet, students select the postulate that is being illustrated to prove congruence between triangles. The worksheet is self-scoring. Once students select the "check your work" link, they are given their...
Lesson Plan
Curated OER

Indirect Proof and Inequalities in One Triangle

For Teachers 10th
In this geometry worksheet, 10th graders order the sides and angles of a triangle and determine the range of the third side of a triangle given the lengths of two sides.  The one page worksheet contains sixteen questions. ...
Worksheet
Curated OER

Eighteen SSS or SAS Triangle Congruence Problems

For Students 9th - 10th
In this triangle congruence worksheet, students state if triangles are congruent and if the congruence is based on side, side, side or the side, angle, side theorems in eighteen problems.  The solutions are found on the last two pages.
Unit Plan
Mathematics Vision Project

Module 6: Congruence, Construction, and Proof

For Teachers 8th - 10th Standards
Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This...
Assessment
Inside Mathematics

Hopewell Geometry

For Teachers 9th - 12th Standards
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
Assessment
Inside Mathematics

Rugs

For Teachers 8th Standards
The class braids irrational numbers, Pythagoras, and perimeter together. The mini-assessment requires scholars to use irrational numbers and the Pythagorean Theorem to find perimeters of rugs. The rugs are rectangular, triangular,...
Assessment
EngageNY

Mid-Module Assessment Task: Grade 7 Mathematics Module 6

For Students 7th Standards
This is a mid-module assessment for the 16th lesson in 29 geometry lessons. Individuals demonstrate their understanding of concepts such as vertical and adjacent angles, constructing geometric figures, and triangle congruence criteria.
Lesson Plan
Curated OER

Exploring the Hinge Theorem

For Teachers 9th - 10th
Learners explore the application of Hinge Theorem. In this geometry lesson, students write inequalities, given two sides of a triangle. They solve problems with triangular inequalities using the proper theorem.
Worksheet
Curated OER

Proving Triangles Congruent

For Students 10th
In this proving triangles congruent learning exercise, 10th graders solve 5 different problems that include proofs and proving congruence in triangles. First, they determine which postulate can be used to prove the triangles congruent...
Lesson Plan
Curated OER

Similarity and Congruence

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

Quiz: Geometric Constructions-Congruence

For Students Higher Ed
In this congruent figures worksheet, students answer ten true or false questions. A sample question reads: "Two triangles are congruent when their shape and size will be the same."
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 9th - 12th
Students are introduced to the Pythagorean theorem. They use three different activities that give students the opportuntiy to observe triangles, and use the Pythagorean theorem and practice different ways of determining areas of...
Lesson Plan
Curated OER

Constructions of Isosceles and Equilateral Triangles

For Teachers 4th - 9th
Young scholars explore the difference between drawing and constructing a triangle utilizing The Geometer's Sketchpad on the computer. They create, develop and script constructions for both isosceles and equilateral triangles. Each...
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers All
Students explore how the Pythagorean Theorem works and how to apply it.
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.
Lesson Plan
Curated OER

Triangles in Architecture

For Teachers 10th - 12th
Students find triangles in the real world. In this geometry lesson plan, students analyze and identify properties of two and three-dimensional objects. They differentiate between similarity and congruence.
Lesson Plan
Futures Channel

Folding Circles

For Teachers 7th - 12th Standards
Students investigate properties of circles. In this geometry lesson plan, students differentiate between similarity and congruence as they observe polygons. They investigate properties of two and three dimensional shape.
Lesson Plan
Curated OER

Euclidean Direct Proofs

For Teachers 9th - 10th
Learning how to prove theorems in geometry can be challenging. This resource explains what a proof is, and the different styles for proofs. It also contains links to web-based practice problems that help guide learners though example...
Lesson Plan
Curated OER

CSI Investigation of Congruence and Similarity

For Teachers 9th - 12th
Students differentiate between similarity and congruence using polygons. In this geometry lesson, students label triangles based on their properties. They find missing sides and angles using the interior sum theorem.
Lesson Plan
Curated OER

SAS Similarity Theorem

For Teachers 9th - 10th
Students identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.
Lesson Plan
Curated OER

Congruence with Robot Gobot

For Teachers 8th - 10th
Students identify the properties of solids and polygons. In this geometry instructional activity, students identify the different measurements of a triangle. They use congruence parts and theorem to prove their answer.
Lesson Plan
Curated OER

An Introductions to Congruent Polygons

For Teachers 8th - 10th
Students differentiate between similar and congruent polygons. For this geometry lesson, students define the theorems and reasons for polygons similarity and congruence. They are given pictures and patterns to differentiate and identify.
Worksheet
Curated OER

Triangle Fundamentals Homework

For Students 9th - 10th
In this geometry worksheet, learners identify the missing angles of non right triangles using the angle sum theorem. They solve for the unknown using algebra. There are 21 questions.