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Lesson Plan
EngageNY

An Area Formula for Triangles

For Teachers 11th - 12th Standards
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
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Lesson Plan
EngageNY

The Definition of Sine, Cosine, and Tangent

For Students 9th - 10th Standards
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar triangles. 
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Assessment
Mathed Up!

Sine and Cosine Rules and Area of Triangles

For Students 9th - 12th
Learners discover how to find missing sides and angles using trigonometry. Scholars first watch a video covering the Law of Sines and Cosines, as well as the area formula for a triangle. To test their knowledge, they complete a learning...
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Unit Plan
1
1
Mathematics Vision Project

Similarity and Right Triangle Trigonometry

For Teachers 10th - 12th Standards
Starting with similar triangles and dilation factors, this unit quickly and thoroughly progresses into the world of right triangle features and trigonometric relationships. Presented in easy-to-attack modules with copious application...
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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.
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Worksheet
Curated OER

Determine the Measure of an Angle of a Right Triangle.

For Students 10th - 11th
In this geometry worksheet, students solve word problems by finding the values of missing angles and missing sides of triangles. They review their trigonometric properties of a right triangle. There are 9 problems with an answer key.
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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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Lesson Plan
West Contra Costa Unified School District

Law of Sines

For Teachers 9th - 12th Standards
Laws are meant to be broken, right? Learners derive the Law of Sines by dropping a perpendicular from one vertex to its opposite side. Using the Law of Sines, mathematicians solve for various parts of triangles.
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Worksheet
Curated OER

Trigonometry Ratios in Right Triangles

For Students 10th
In this trigonometry ratios in right triangles worksheet, 10th graders solve 10 different trigonometric ratios that apply to right triangles. First, they define a trigonometric ratio and its three most common ratios, sine, cosine, and...
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Worksheet
Curated OER

Similar Right Triangles-Introductions to Trigonometry

For Students 9th - 10th
In this geometry worksheet, students examine similar right triangles as the basis for the foundation of trigonometry. Students define the basic trigonometric functions and use a calculator to find the trigonometric value of an angle. The...
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Worksheet
Curated OER

Special Right Triangles

For Students 10th
In this special right triangles activity, 10th graders solve 10 different problems that include solving equations that are special right triangles. First, they determine the exact value of each problem. Then, students use the Pythagorean...
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Worksheet
Curated OER

Triangles

For Students 6th - 10th
For this triangles worksheet, students solve for the missing angles and missing sides on the triangles given. Students complete 12 problems total.
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Lesson Plan
Curated OER

Review Geometry - Week 8 (Triangles)

For Teachers 11th - 12th
In this triangle worksheet, students use similar figures to find the length of one side of two similar triangles. They find the area of a triangle inscribed in a rectangle. This two-page worksheet contains eight problems.
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Worksheet
Curated OER

Right Triangle Stuff

For Students 12th - Higher Ed
In this right triangle activity, students use trigonometric ratios to find the hypotenuse, right angle, opposite leg and angles. This one-page activity contains eight problems. Answers are provided at the bottom of the page.
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Worksheet
Curated OER

Trigonometry

For Students 10th
For this geometry worksheet, 10th graders solve problems that are based on the right triangle trigonometry and the special right triangles. The three page worksheet contains twelve questions.  Answers are not included. 
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Assessment
EngageNY

End-of-Module Assessment Task: Pre-Calculus Module 4

For Students 11th - 12th Standards
Challenge your scholars to show what they know about the Law of Sines, Law of Cosines, and inverses. The six-question assessment is the last in a series of 16. Pupils find the area of triangles and show that the Law of Sines and Law of...
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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. When...
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Lesson Plan
Project Maths

Introduction to Trigonometry

For Teachers 9th - 12th Standards
The topic of trigonometric ratios is often covered with loads of rote memorization baked into the activity. This activity set, however, leans more on using similar triangles and discovery learning to help young geometers develop a deeper...
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Handout
2
2
Curated OER

Trig Cheat Sheet

For Teachers 10th - 12th Standards
Your pre-calculus learners will make use of this wonderful cheat sheet that summarizes all things trigonometric. Definitions based on both the unit circle and the right triangle are included, as well as many convenient trigonometric...
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Handout
2
2
Curated OER

Trigonometry Review Sheet

For Students 9th - 12th Standards
Get the trig facts fast, and use the review sheet as a guide in the classroom. The worksheet also includes a document version if any changes are needed to the problems. The information includes a small degree/radian chart, a graph of all...
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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.
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Worksheet
Curated OER

Triangle and Circle Trigonometry

For Students 11th - 12th
In this Pre-calculus/Trigonometry worksheet, learners apply advanced triangle and circle trigonometry to solve application problems. The three page worksheet contains sixteen problems. Answers are not included.
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Worksheet
Curated OER

Review of Trig Ratios

For Students 11th - Higher Ed
In this trigonometric ratios worksheet, students solve and complete 10 various types of problems. First, they write the degrees listed in radian measure. Then, students find the exact ratios for each equation. They also find the value of...
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Worksheet
1
1
Curated OER

Right Triangle Trigonometry: Evaluating Trigonometric Ratios

For Students 10th - 12th
In this right triangle trigonometry instructional activity, 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 instructional activity...