Lesson Plan
Curated OER

Solve Right Triangle

For Teachers 9th - 11th
In this trigonometric applications worksheet, students solve for the missing side of a right triangle using a trigonometric ratio. There are 46 questions, 10 of which are word problems.
Lesson Plan
Curated OER

Medians and Altitudes of Triangles

For Teachers 10th
In this geometry worksheet, 10th graders determine if a given segment is a median or altitude of a triangle and use then find the indicated missing length or equation of a line.  The two page worksheet contains twenty...
Lesson Plan
EngageNY

Prove the Pythagorean Theorem Using Similarity

For Students 9th - 10th Standards
Amaze your classes with the ability to find side lengths of triangles immediately — they'll all want to know your trick! Learners use the Pythagorean Theorem and special right triangle relationships to find missing side lengths.
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...
Lesson Plan
EngageNY

Applying the Laws of Sines and Cosines

For Students 9th - 10th Standards
Breaking the law in math doesn't get you jail time, but it does get you a wrong answer! After developing the Law of Sines and Cosines in lesson 33 of 36, the resource asks learners to apply the laws to different situations. Pupils must...
Worksheet
Curated OER

Right Triangle Trigonometry: Finding Missing Sides and Angles

For Students 9th - 11th
In this right triangle trigonometry worksheet, students find the measure of specified angles. Students determine the length of the missing side of a right triangle. This four-page worksheet contains 24 problems. Answers to the worksheet...
PPT
Curated OER

Classifying Triangles

For Teachers 3rd - 5th
If you're looking for a presentation to assist you in your teaching of triangles, this one could be for you. In it, learners are shown how triangles are classified by the size of their angles and by their sides. These are tricky concepts...
Interactive
CK-12 Foundation

Identify Accurate Drawings of Triangles: Law of Cosines

For Students 10th - 12th Standards
Drawing triangles is easy, even if you have to calculate the exact length of its sides. Scholars use the Law of Cosines to find missing sides of triangles. An interactive helps them check their answers.
Lesson Plan
EngageNY

Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles

For Students 9th - 10th Standards
Why are right triangles so special? Pupils begin their study of right triangles by examining similar right triangles. Verifying through proofs, scholars recognize the three similar right triangles formed by drawing the altitude. Once...
Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 6th - 10th
In this Pythagorean theorem worksheet, students use the Pythagorean theorem to find the missing side of the triangle. Students complete 10 problems.
Lesson Plan
EngageNY

Informal Proof of the Pythagorean Theorem

For Students 8th Standards
Prove the Pythagorean Theorem using multiple informal proofs. Scholars first develop an understanding of the origins of the Pythagorean Theorem through proofs. They round out the lesson plan by using the theorem to find missing side...
Lesson Plan
EngageNY

Applications of the Pythagorean Theorem

For Students 8th Standards
Begin seeing the world through the lens of geometry! Use the 19th installment in a 25-part module to apply the Pythagorean Theorem to solve real-world problems. Individuals sketch situations resulting in right triangles such as the...
Lesson Plan
Curated OER

Triangle Sum Theorem

For Teachers 9th - 12th Standards
Teach your class how to solve problems using the triangle sum theorem. In this geometry lesson, students identify the missing angles in a triangle using the sum theorem. They graph triangles on the TI and moves the sides around to create...
Worksheet
1
1
Curated OER

Right Triangle Trigonometry: Evaluating Trigonometric Ratios

For Students 10th - 12th
In this right triangle trigonometry learning exercise, students use trigonometric ratios to determine the length of a missing side of a triangle or to find a specified angle measurement. This four-page learning exercise contains 32...
Lesson Plan
Curated OER

Corresponding Parts of Similar Triangles

For Teachers 9th - 12th Standards
Here is a lesson that has learners take a look at corresponding parts of similar triangles, ratios of similarity, reductions and enlargements. They'll manipulate the scale factor (r) to observe the changes in similar triangles and then...
Lesson Plan
Curated OER

Law of Sines

For Teachers 10th - 12th
In this Law of Sines worksheet, learners describe, in their own words, when to use the law of sines. They give an example of a problem using the law of sines. This two-page worksheet contains one problem and a sample answer.
Lesson Plan
Curated OER

Area Measures and Right Triangles

For Teachers 9th - 12th Standards
Your class will investigate the relationship among different triangles. This geometry lesson, demonstrates how to make a connection between triangles and the Pythagorean Theorem. They identify the missing side or angle of a triangle.
Worksheet
McGraw Hill

The Wellness Triangle

For Students 6th - 9th
Health is not simply the absence of disease or a one-dimensional notion, but is really a combination of physical, emotional, and social components. Discover the wellness triangle, which not only includes signs of health and ways to...
Worksheet
Curated OER

Missing Angle Measures

For Students 5th - 8th
In this missing angle measures activity, students subtract the angle that is given from 180' to find the missing angle measure. Students complete 6 problems.
Lesson Plan
EngageNY

Using Trigonometry to Find Side Lengths of an Acute Triangle

For Students 9th - 10th Standards
Not all triangles are right! Pupils learn to tackle non-right triangles using the Law of Sines and Law of Cosines. After using the two laws, they then apply them to word problems. 
Lesson Plan
EngageNY

Comparing the Ratio Method with the Parallel Method

For Students 9th - 10th Standards
Can you prove it? Lead your class through the development of the Side Splitter Theorem through proofs. Individuals connect the ratio and parallel method of dilation through an exploration of two proofs. After completing the proofs,...
Activity
Education Development Center

Similar Triangles

For Students 8th - 10th Standards
Model geometric concepts through a hands-on approach. Learners apply similar triangle relationships to solve for an unknown side length. Before they find the solution, they describe the transformation to help identify corresponding sides.
Lesson Plan
Curated OER

Algebra 2 & Trigonometry Practice: Law of Sines

For Teachers 9th - 12th
In this law of sines worksheet, students solve 9 multiple choice and short answer problems.  Students use the law of sines to missing side lengths and angles of triangles.
Worksheet
Curated OER

Pythagorean Theorem

For Students 7th - 10th
For this Pythagorean Theorem worksheet, students use the Pythagorean Theorem to find the missing side of a triangle. Students complete 10 problems.