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Lesson Plan
Virginia Department of Education

Special Right Triangles and Right Triangle Trigonometry

For Teachers 9th - 11th Standards
Right triangles are so special! Use special right triangles to discover the trigonometric ratios. Pairs construct special right triangles and find the values of the ratios of the sides. In the process, they discover the ratios stay the...
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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...
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Lesson Plan
Curated OER

Special Right Triangles

For Teachers 9th - 12th Standards
Using the Pythagorean Theorem to solve for missing angles, students evaluate right triangles and their properties.
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Worksheet
Curated OER

Area of Right Triangles

For Students 8th - 10th
In this are of right triangles worksheet, students read graphs and explore congruent triangles.  They find the area of rectangles and of right triangles.  This one-page worksheet contains explanations, instructions, and 8 problems.
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Lesson Plan
Curated OER

Investigating Segments in a Right Triangle

For Teachers 9th - 12th Standards
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
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Lesson Plan
Curated OER

30-60-90 Right Triangles in Cabri Jr.

For Teachers 9th - 12th Standards
Young mathematicians draw and label right triangles using Cabri Jr. technology. They create other special right triangles and identify the length of the hypotenuse and each leg. High schoolers explore the ratios to determine how the...
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Lesson Plan
Curated OER

Trigonometric Functions of Acute Right Triangles

For Teachers 9th - 11th
Students derive the six trigonometric functions. In this trigonometry lesson, students show their understanding of trigonometric functions as they relate the right triangles. They find the missing angles and side use trig ratios of sine,...
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Worksheet
Kim Brassard

Solving Right Triangles

For Students 7th - 10th
Solve that triangle! Your class examines angles and side measurements on 20 right triangles to determine the missing measurements. For some, they are given two sides while for others, they are given an angle and a side.
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Worksheet
Curated OER

Right Triangles

For Students 10th
For this right triangles worksheet, 10th graders solve 10 different problems that include various right triangles. First, they find the value of a base given its hypotenuse. Then, students determine an angle given the perimeter and...
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Unit Plan
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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
Mathalicious

Been Caught Stealing

For Teachers 6th - 8th Standards
You're safe, when calculating the odds of stealing second base! Learners compare the rate of a runner to the distance the ball travels, in a lesson that explores right triangles and measurement. Full of discussion questions and fun...
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Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve 6 various problems and figures related to right triangles. First they identify and describe the 3 theorems and 1 postulate stated that prove 2 right triangles congruent if one of them...
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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 6 different right triangle problems. First, they find the values of x and y in each triangle, rounding each to the nearest tenth. Then, students locate the...
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Assessment
Inside Mathematics

Circles in Triangles

For Teachers 9th - 12th Standards
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
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Worksheet
1
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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...
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Lesson Plan
Curated OER

Roofing and Right Triangles

For Teachers 9th - 11th
Young scholars use models and symbols to represent properties of the Pythagorean Theorem. For this right triangle lesson, students connect real jobs to properties of right triangles. They solve word problems applying the correct ratios...
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Lesson Plan
Curated OER

Applying Special Right Triangles

For Teachers 10th
For this geometry worksheet, 10th graders use the theorems regarding right triangles to find the missing length in a special right triangle. The one page worksheet contains eleven questions. Answers are included.
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Assessment
Balanced Assessment

Refiguring Pythagoras

For Students 6th - 8th
Why was Pythagoras so obsessed with squares? The assessment task posits the question of whether the geometric interpretation of the Pythagorean Theorem holds for figures other than squares. Scholars first consider the case of semicircles...
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Lesson Plan
EngageNY

The Converse of the Pythagorean Theorem

For Teachers 8th Standards
Is it a right triangle or not? Introduce scholars to the converse of the Pythagorean Theorem with a lesson that also provides a proof by contradiction of the converse. Pupils use the converse to determine whether triangles with given...
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Lesson Plan
Curated OER

Right Triangles

For Teachers 7th - 8th
In this right triangles worksheet, students solve and complete 2 different types of problems. First, they take the case of an isosceles right triangle with a given leg and hypotenuse. Then, students find the sum of the squares of the...
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Worksheet
Curated OER

Special Right Triangles

For Students 10th
In this special right triangles worksheet, 10th graders solve 7 various problems with various types of right triangles. First, they identify the two special types of right triangles, the 45-45-90 degree triangle and the 30-60-90 right...
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Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles activity, 10th graders solve 10 different problems that include determining the means proportionally in each right triangle. First, they use the given information to determine the measure of each line segment....
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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

Right Triangle

For Students 8th - 9th
In this right triangle activity, students find the length of sides of a right triangle. This one-page activity contains 1 problem.