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Interactive
CK-12 Foundation

Pythagorean Theorem for Solving Right Triangles: Solving the Triangle

For Students 9th - 12th Standards
Observe the change in the trigonometric ratios as angles vary. An interactive provides the values of trigonometric ratios for both acute angles in a right triangle. Pupils create a right triangle to match given criteria and find the...
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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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Interactive
CK-12 Foundation

Lengths of Sides in Isosceles Right Triangles: Paper Football

For Students 9th - 12th Standards
Fuse sports and geometry by having your class create paper footballs—that are actually isosceles right triangles! Scholars use an interactive to create an isosceles right triangle to model a paper football. From the information in the...
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Interactive
CK-12 Foundation

Relationships of Sides in 30-60-90 Right Triangles: Truck on a Mountain Road

For Students 9th - 12th Standards
Determine the change in elevation on a mountain road. Individuals use the interactive to simulate a truck driving up a mountain road with a 30-degree incline. They determine missing sides of a 30-60 right triangle to find horizontal and...
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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.
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Instructional Video7:06
2
2
Flipped Math

Unit 7 Review: Right Triangles

For Students 9th - 12th Standards
It is all right to spend some time with a review. After watching a short review video covering the materials from the unit, pupils work through 23 review problems. Scholars work on problems involving the Pythagorean Theorem and its...
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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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Interactive
CK-12 Foundation

Special Triangle Ratios: Special Right Triangle Ratios

For Students 9th - 12th Standards
Go from one side length to any other side length with special right triangles. Individuals use the interactive to investigate the ratio of sides in 45-45 and 30-60 right triangles. Scholars make generalizations about the types of special...
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Interactive
CK-12 Foundation

Right Triangles, Bearings, and Other Applications: Sailing Race

For Students 9th - 12th Standards
Help your class get their bearings when it comes to right triangles. Pupils determine distances traveled or components given the bearing of a sailboat using an interactive. The scholars develop a sense of finding the bearings of a given...
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Interactive
CK-12 Foundation

Distance Formula: Right Triangles

For Students 8th - 10th Standards
Go the distance with a far out resource. Individuals use an interactive to create right triangles on a coordinate plane to help find distance between two points. Challenge questions aid them in developing the distance formula.
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Unit Plan
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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
1
1
Illustrative Mathematics

Applying the Pythagorean Theorem in a Mathematical Context

For Teachers 7th - 9th Standards
Participants who use this resource will apply the Pythagorean Theorem to show whether or not the shaded triangle inscribed in a rectangle is a right triangle. Once all of the sides on the shaded triangle are found, it is important that...
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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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Interactive
CK-12 Foundation

Lengths of Triangle Sides Using the Pythagorean Theorem: Find the Missing Side

For Students 8th - 12th Standards
What is the relationship between the sides of a right triangle? Learners use an interactive to create models of right triangles and view the relationship between the lengths of the sides. They finish by using the Pythagorean Theorem to...
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Interactive
CK-12 Foundation

Identifying Sets of Pythagorean Triples: Matching Problem

For Students 8th - 12th Standards
What sets of whole numbers make up the measures of side lengths in right triangles? Pupils use an interactive triangle to learn about Pythagorean triples. Individuals find missing values in triples and learn more about Pythagorean...
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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
Mathematics Assessment Project

Hopewell Geometry

For Students 8th - 10th Standards
Right triangles from 2,000 years ago? Learners investigate different right triangles found in the earthworks of the Hopewell people, a Native American culture that populated the United States from 200BC to AD 500. Learners apply concepts...
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Lesson Plan
1
1
Illustrative Mathematics

Right Triangles Inscribed in Circles II

For Teachers 9th - 10th Standards
So many times the characteristics of triangles are presented as a vocabulary-type of activity, but in this activity they are key to unraveling a proof. A unique attack on proving that an inscribed angle that subtends a diameter must be a...
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Worksheet
Curated OER

Similarity

For Students 10th
In this similarity worksheet, 10th graders solve and complete 14 different types of problems. First, they refer to each drawn figure given that the lines are parallel. Then, students find the length of each segment listed. In addition,...
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Lesson Plan
Curated OER

Investigating Trigonometric Ratios Through Similar Right Triangles.

For Teachers 8th - 10th
49Students investigate the properties of right triangles. In this geometry lesson, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.
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Unit Plan
Mathematics Vision Project

Module 4: Similarity and Right Triangle Trigonometry

For Teachers 9th - 12th Standards
Right you are to use a great resource. Starting with a lesson on dilations, scholars learn about similarity transformations and similar triangles. They use the knowledge to develop an understanding of right triangle trigonometry in later...
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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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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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Interactive
CK-12 Foundation

Pythagorean Theorem to Classify Triangles: Missing Angles

For Students 8th - 12th Standards
Learn to use the Pythagorean Theorem with non-right triangles. Pupils use the interactive to discover the relationship between the lengths of sides for acute and obtuse triangles. They compare the squares of the sides of the triangles to...