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Right Triangles

  • Pythagorean Theorem
  • Special Right Triangles
  • Trigonometric Ratios

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  • Right Triangles Lesson Plans
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Right Triangles Teacher Resources

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Find Right Triangles lesson plans and worksheets
Showing 1,390 resources
30 Items in Unit
Geometry Unit 7: Right Triangles
Lesson Planet Curated

Geometry Unit 7: Right Triangles

For Students 9th - 12th Standards
Six lessons comprise the Geometry Unit 7: Right Triangles unit module. In the first lesson, pupils review the Pythagorean Theorem and determine how to use the converse to determine whether a triangle is right, obtuse, or acute. Next,...
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24 Items in Unit
Geometry Unit 4: Triangle Congruence
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Geometry Unit 4: Triangle Congruence

For Teachers 9th - 12th Standards
The Geometry Unit 4: Triangle Congruence unit module contains five lessons—each with a video, teacher reference, practice packets, solutions, and corrective assignments. To begin, scholars review the types of triangles, then investigate...
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12 Items in Topic
Getting into Trig
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Getting into Trig

For Teachers 9th - 12th Standards
Starting with right triangles (SOH-CAH-TOA) and working up to the concept of radians, this collection introduces students to trigonometric ratios and supports them in learning to evaluate trigonometric functions.
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12 Items in Course
Flipped Math: Geometry
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Flipped Math: Geometry

For Students 9th - 12th Standards
Imagine taking a complete geometry course remotely! Eleven units make up the My Geometry course. Each unit follows the Flipped-Mastery cycle of learning, divided into two semesters. Pupils watch and take notes on a video that details the...
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29 Items in Unit
Geometry Unit 9: Area of Polygons
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Geometry Unit 9: Area of Polygons

For Teachers 9th - 12th Standards
Six lessons make up the Geometry Unit 9: Area of Polygons unit module. Pupils review the formulas for finding the area of parallelograms and triangles. They apply previous learning of trigonometric ratios and the Pythagorean Theorem to...
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12 Items in Topic
Math Antics Geometry Video Lessons
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Math Antics Geometry Video Lessons

For Teachers 4th - 8th Standards
The point of this collection of 12 videos is to introduce learners to three basic parts of geometry—points, lines, and planes. The presenter provides definitions, shows how to classify shapes, provides examples, and shows how to use...
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10 Items in Topic
Mathematics Vision Project: Interactive Applets
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Mathematics Vision Project: Interactive Applets

For Students 9th - 12th Standards
Ready, set, go! The Mathematics Vision Project provides a collection of 10 Interactive Applets that follow the progression of learning—to practice, develop, and solidify understanding. The interactives use engaging materials that include...
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12 Items in Unit
Common Core Algebra 2, Unit 9
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Common Core Algebra 2, Unit 9

For Teachers 9th - 12th Standards
Flip your classroom, or offer engaging visual aids to your lessons with a series of videos that explore the concept of trigonometry. After an introduction to the topic, high schoolers investigate reference triangles, unit circles, and...
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3 Items in Topic
Grade 9-12, Claim 2 & 4: Problem Solving & Communication Reasoning Supports
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Grade 9-12, Claim 2 & 4: Problem Solving & Communication Reasoning Supports

For Teachers 9th - 12th Standards
Small but mighty, a collection of three resources features presentation slides that prepare high schoolers for the Smarter Balanced assessment. Claim 2 features problem solving questions drawn from all content areas. Claim 3 focuses on...
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10 Items in Topic
Grade 8, Claim 1: Concepts and Procedures Item Slide Shows
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Grade 8, Claim 1: Concepts and Procedures Item Slide Shows

For Teachers 8th Standards
Ten resources make up a collection of student and teacher-friendly slides that prepare eighth graders for the Smarter Balance assessment. Learners review rational and irrational numbers, convert repeating decimals to fractions, as well...
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Instructional Video2:49
How Do You Determine if a Triangle Is a Right Triangle if You Know its Sides? Instructional Video
Curated OER

How Do You Determine if a Triangle Is a Right Triangle if You Know its Sides?

For Teachers 6th - 10th
Use the Pythagorean Theorem formula to check if this given triangle, with the given lengths of each side, is a right triangle. It's as simple as plugging the given values into the formula and doing the math to see if the solution checks...
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Instructional Video2:12
What are the Legs and Hypotenuse of a Right Triangle? Instructional Video
Curated OER

What are the Legs and Hypotenuse of a Right Triangle?

For Teachers 6th - 10th
What are all the parts of a right triangle called? What makes it a right triangle? Legs? Triangles have legs? Hypotenuse? Pythagorean Theorem? The instructor diagrams and identifies all the parts of a right triangle for you.
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Instructional Video2:47
How Do You Find the Sine of an Angle in a Right Triangle? Instructional Video
Curated OER

How Do You Find the Sine of an Angle in a Right Triangle?

For Teachers 7th - 11th
A trigonometric ratio is a ratio between two sides of a right triangle. In this problem, find sin(A) in the given right triangle. Use the ratio of the opposite side over the hypotenuse.
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Instructional Video5:07
How Do You Find a Missing Side of a Right Triangle Using Cosine? Instructional Video
Curated OER

How Do You Find a Missing Side of a Right Triangle Using Cosine?

For Teachers 6th - 11th
Trigonometry? What's trigonometry. Well, something to do with triangles, right? Right! Right triangles! In this problem, find the missing length of one of the sides. So set this up as a ratio: cosine(A) = adjacent side length divided by...
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Instructional Video3:45
Special Right Triangle 45-45-90: Lesson Instructional Video
CK-12 Foundation

Special Right Triangle 45-45-90: Lesson

For Students 8th - 11th
Square roots connect squares and right triangles. Using the Pythagorean Theorem, the video shows the relationship between the sides and hypotenuse of a 45-45 right triangle. The portion of a larger geometry playlist applies the...
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Interactive
Pythagorean Theorem for Solving Right Triangles: Solving the Triangle 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
Special Right Triangles and Right Triangle Trigonometry Lesson Plan
Odell 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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Instructional Video3:40
How Do You Find Missing Angles in an Isosceles Triangle Using Right Triangles? Instructional Video
Curated OER

How Do You Find Missing Angles in an Isosceles Triangle Using Right Triangles?

For Teachers 6th - 8th
Given an isosceles triangle, and the value of one angle, find the missing values. There are some special properties about isosceles triangles. Use the triangle sum theorem to solve this problem. Watch this video to see how the instructor...
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Instructional Video3:21
How Do You Find the Cosine of an Angle in a Right Triangle? Instructional Video
Curated OER

How Do You Find the Cosine of an Angle in a Right Triangle?

For Teachers 7th - 11th
What's a trigonometric ratio? It is a ratio between two sides of a right triangle. In this problem, find cosine(A) in the given right triangle. Use the ratio of the adjacent side divided by the hypotenuse to find cos(A). The instructor...
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Instructional Video3:13
How Do You Find the Tangent of an Angle in a Right Triangle? Instructional Video
Curated OER

How Do You Find the Tangent of an Angle in a Right Triangle?

For Teachers 6th - 11th
What's a trigonometric ratio? It is a ratio between two sides of a right triangle. In this problem, find tangent(A) in the given right triangle. Use the ratio of the opposite side divided by the adjacent side to find tan(A). The...
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Instructional Video3:34
How Do You Find a Missing Angle in a Right Triangle? Instructional Video
Curated OER

How Do You Find a Missing Angle in a Right Triangle?

For Teachers 6th - 8th
The triangle sum theorem states that the interior angles of a triangle add up to 180 degrees. So it seems logical that if there are two known values given for the interior angles of a triangle, the third value could be found using this...
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Instructional Video5:06
How Do You Find a Missing Side of a Right Triangle Using Tangent? Instructional Video
Curated OER

How Do You Find a Missing Side of a Right Triangle Using Tangent?

For Teachers 6th - 11th
Identify the variables, identify the given values and use a formula to find the missing length in this right triangle problem. What formula? The tangent ratio, which is normally used to show a ratio between two sides of a right triangle,...
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Instructional Video4:09
How Do You Find the Length of a Leg of a Right Triangle? Instructional Video
Curated OER

How Do You Find the Length of a Leg of a Right Triangle?

For Teachers 6th - 9th
A right triangle. Two given measurements for two side lengths and one unknown length. Use the Pythagorean theorem to solve this problem and find the missing value. Squares and square roots are used in this problem and don't worry when...
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Instructional Video9:40
Intro to 30-60-90 Triangles, Right Triangles and Trigonometry, Geometry Instructional Video
Khan Academy

Intro to 30-60-90 Triangles, Right Triangles and Trigonometry, Geometry

For Students 9th - 10th
As the fourth part of a series on the Pythagorean Theorem, Sal continues an exploration of the ways to calculate the length of sides of a right triangle using algebra. He also used this theorem to solve problems involving a right...
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