Interactive
Curated OER

Congruent Triangles Multiple Choice

For Students 8th - 10th
For this geometry worksheet, students differentiate between congruent and similar triangles. They solve for the missing angle using triangular theorem. There are 5 questions with an answer key.
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

Putting the Law of Cosines and the Law of Sines to Use

For Teachers 11th - 12th Standards
Use the Law of Cosines and the Law of Sines to solve problems using the sums of vectors. Pupils work on several different types of real-world problems that can be modeled using triangles with three known measurements. In the process,...
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

Identifying Similar Triangles

For Students 10th
In this identifying similar triangles instructional activity, 10th graders solve 6 different types of problem that include identifying and comparing similar triangles. First, they identify the three ways that determine whether two...
Lesson Plan
Curated OER

Similar Triangles

For Teachers 9th - 10th
Students differentiate between similar and congruent triangles. In this geometry lesson, students identify the missing side and angle of a triangle. They identify the different ratio and proportion of the sides of a triangle.
Worksheet
Curated OER

Recognize Triangles

For Students Pre-K - 1st
In this shapes learning exercise, students are asked to "colour" all of the triangles they find on the page. There are 10 shapes on the page and 4 are triangles. The second page contains suggestions for teachers on activities with 2-D...
Lesson Plan
Curated OER

Special Right Triangles

For Teachers 7th - 9th
Young scholars identify the different parts of a right triangle. In this geometry lesson, students use the Pythagorean Theorem to identify missing sides and angles of a right triangle. They work with irrational and rational roots.
Lesson Plan
Houghton Mifflin Harcourt

Developing the Concept: Triangles and Quadrilaterals

For Teachers 5th - 7th Standards
Exact narrative and examples make this lesson on polygons easy to implement. Through it, your class will learn how to use a protractor and ruler to construct triangles and quadrilaterals according to your directions. Your class will be...
Lesson Plan
EngageNY

Solving Problems Using Sine and Cosine

For Students 9th - 10th Standards
Concepts are only valuable if they are applicable. An informative resource uses concepts developed in lessons 26 and 27 in a 36-part series. Scholars write equations and solve for missing side lengths for given right triangles....
Performance
Radford University

Developing a Trigonometry Phone App

For Teachers 9th - 12th Standards
What's one more app? After reviewing how to calculate missing side lengths or angle measures in a right triangle, pupils create instructions for a phone app to do all of the tedious work. They must consider all nine cases of known...
Worksheet
Curated OER

The Pythagorean Theorem

For Students 9th
In this Pythagorean theorem worksheet, 9th graders solve and complete 8 different problems that include using the Pythagorean theorem to solve. First, they find the missing measure in each right triangle. Then, students make a drawing...
Workbook
1
1
Utah Education Network (UEN)

Real World Equations and Inequalities

For Students 7th Standards
Use of the resource = Opportunities for increased learning. Learners must use equations and inequalities to solve real-world and geometric problems.
Worksheet
Curated OER

Polygon Sum Conjecture

For Students 10th
For this geometry worksheet, 10th graders identify the missing angles using the polygons sum conjecture. They measure exterior and interior angles using their angle theorems. There are 63 problems.
Lesson Plan
Curated OER

How are Trig Ratios Used to Measure Triangle Sides

For Teachers 8th - 11th
Students identify the ratios of trig identities. In this geometry lesson, students solve the missing sides and angles of triangles using trig ratios. They relate the graphs and waves to real life scenarios.
Lesson Plan
Curated OER

Review of Triangles

For Teachers 8th - 10th
Learners investigate the Pythagorean Theorem. In this geometry lesson, students define angles and sides of right triangles. They calculate the area and surface area using formulas derived by the Pythagorean Theorem.
Worksheet
Curated OER

Applied Trigonometry Problems Day 2

For Students 9th - 10th
In this geometry instructional activity, students apply right triangle trigonometry to find missing distances or angles in real life examples involving angles of depression or elevation. The four page instructional activity contains...
Worksheet
Curated OER

Pythagorean Theorem Homework

For Students 9th - 10th
In this Pythagorean theorem worksheet, students determine if given side lengths for right triangles, find the length of the missing side in right triangles, and find the length of the diagonals formed in boxes given side lengths.
Worksheet
Curated OER

Applied Trigonometry Problems

For Students 9th - 12th
In this applied trigonometry problems worksheet, students solve 12 short answer word problems. Students use trigonometric ratios to find angles of elevation and depression. Students find distances between objects using trigonometric...
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...
Unit Plan
Mathematics Vision Project

Module 5: Modeling with Geometry

For Students 9th - 12th Standards
Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts...
Lesson Plan
Utah Education Network (UEN)

It's All Just Similar to Me

For Teachers 7th - 8th
Middle schoolers explore the concept of similar figures. In this similar figures lesson, pupils calculate scale factors of similar triangles. They find missing sides of triangles, and measure angles using protractors and measure sides of...
Lesson Plan
Curated OER

Investigating Trigonometric Ratios Through Similar Right Triangles

For Teachers 9th - 10th
Pupils identify similar and congruent right triangles. In this geometry lesson, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.
Worksheet
Curated OER

Section 8-6: Solving Problems Using Trigonometric Ratios

For Students 9th - 12th
For this trigonometric ratios worksheet, students solve 20 short answer and multiple choice problems.  Students use trigonometric ratios, the angle of depression, and angle of elevation to find missing side lengths of angles of a...