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Interactive
Curated OER

Trigonometry Applications

For Students 10th
In this geometry worksheet, 10th graders solve application word problems involving the use or right triangle trigonometry, including angle of elevation or depression. The one page interactive worksheet contains five questions. Hints,...
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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...
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Handout
Charleston School District

3D Applications of the Pythagorean Theorem

For Students 8th - 10th Standards
How many right triangles can you find in a prism, cone, or pyramid? Using right triangles to find lengths in three-dimensional figures is the focus of the lesson. After working with the Pythagorean Theorem to find missing side lengths...
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Lesson Plan
Virginia Department of Education

The Pythagorean Relationship

For Teachers 9th - 11th Standards
Add up areas of squares to discover the pythagorean relationship. Small groups create right triangles with squares along each side. They calculate the areas of each square and notice the relationship. Groups construct other types of...
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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. 
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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...
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Lesson Plan
EngageNY

From Circle-ometry to Trigonometry

For Students 10th - 12th Standards
Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.
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Interactive
Shodor Education Foundation

Pythagorean Explorer

For Students 6th - 12th Standards
Make sure the measurement is right. The interactive provides right triangles with a missing side measurement. Pupils use the given sides and the Pythagorean Theorem to calculate the length of the missing side. After entering the length,...
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Worksheet
Curated OER

Unit 5: Worksheet 3 - Similar Triangles

For Students 8th - 9th
In this similar triangles worksheet, students use proportions to solve for the missing sides of similar triangles. This two-page worksheet contains 16 multi-step problems.
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Worksheet
Curated OER

Right Triangle Trigonometry

For Students 10th
In this geometry worksheet, 10th graders use right triangle trigonometry to find the missing angle measure.  The two page worksheet contains fourteen problems.  Answers are provided. 
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Handout
Charleston School District

Pythagorean Theorem and Converse

For Students 8th Standards
You've heard that it is true, but can you prove it? Scholars learn the Pythagorean Theorem through proof. After an overview of proofs of the theorem, learners apply it to prove triangles are right and to problem solve. This is the second...
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Assessment
Mathed Up!

Trigonometry

For Students 10th - 12th
Learn how to solve a triangle. Young mathematicians view a video that explains how to apply trigonometry to find missing sides and angles of a right triangle. A activity tests their understanding of the concept.
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Lesson Plan
Curated OER

Mathematical Modeling

For Teachers 9th - 12th
Study various types of mathematical models in this math lesson plan. Learners calculate the slope to determine the risk in a situation described. They respond to a number of questions and analyze their statistical data. Then, they...
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Lesson Plan
Curated OER

The Greedy Triangle-Intro to Geometric Shapes

For Teachers 4th - 6th Standards
 In this geometry lesson plan, learners read The Greedy Triangle and use geoboards to construct geometric shapes. They identify the number of sides and angles each shape has.
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Lesson Plan
EngageNY

Converse of the Pythagorean Theorem

For Students 8th Standards
Discover a new application of the Pythagorean Theorem. Learners prove and apply the converse of the Pythagorean Theorem in the 17th lesson in a 25-part series. The examples ask learners to verify right triangles using the converse of the...
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Interactive
CK-12 Foundation

Pythagorean Theorem and Its Converse

For Students 8th - 10th
To be a right triangle, or not to be — that is the question. Scholars drag line segments in an Internet application to see if they form right triangles. Once they get the results of the activity, they connect them to the converse of the...
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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...
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Lesson Plan
Illustrative Mathematics

Area of a Trapezoid

For Teachers 7th - 9th Standards
Here is a straightforward example of how to apply the Pythagorean Theorem to find an unknown side-length of a trapezoid. Commentary gives additional information on proving that the inside of the trapezoid is a rectangle, but is...
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Instructional Video20:08
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2
Flipped Math

Trig Ratios

For Students 9th - 12th Standards
Take ratios of sides to a new level. Pupils learn the definitions of the three basic trigonometric ratios in right triangles. Using the definitions, scholars find missing lengths in right triangles, based on a known angle. Individuals...
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Instructional Video24:21
2
2
Flipped Math

Intro to Trigonometry

For Students 9th - 12th Standards
Expand trigonometric ratios beyond right triangles. Pupils start with a review of trigonometric ratios and then take a look at angles in standard position to determine their measurements. Scholars discover how to find coterminal angles...
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Lesson Plan
Curated OER

Applications of Triangles

For Teachers 9th - 11th
Students apply the properties of a right triangle. In this triangle lesson, students describe and compare radians to degrees. They solve problems using the properties and ratios of a right triangle.
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Activity
Illustrative Mathematics

Slopes and Circles

For Teachers 9th - 12th Standards
An upper-level treatment of what is often presented as a basic concept (the right angle of an inscribed circle on the diameter), this activity really elevates the mathematical thought of the learner! Expected to develop formulas from...
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Lesson Plan
EngageNY

Law of Sines

For Teachers 11th - 12th Standards
Prove the Law of Sines two ways. The ninth segment in a series of 16 introduces the Law of Sines to help the class find lengths of sides in oblique triangles. Pupils develop a proof of the Law of Sines by drawing an altitude and a second...
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Lesson Plan
Curated OER

Triangle Classificaition with Geometer's Sketchpad.

For Teachers 7th - 12th
Students use Geometer's Sketchpad to draw triangles and explore the classificaiton of each using the mearsures of interior angles and the lengths of the sides.