Virginia Department of Education
Special Right Triangles and Right Triangle Trigonometry
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...
West Contra Costa Unified School District
Investigating Special Right Triangles
Scholars first investigate relationships in the side lengths of 30°-60°-90° triangles and 45°-45°-90° triangles. This knowledge then helps them solve problems later in the lesson plan about special right triangles.
Flipped Math
Special Right Triangles II
Show students that right triangles are radical. Learners see how the lengths of the sides of a 45-45-90 triangle relate. Using that relationship, pupils observe how to find any of the lengths given one side of a triangle. They go on to...
EngageNY
Special Relationships Within Right Triangles—Dividing into Two Similar Sub-Triangles
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...
Flipped Math
Special Right Triangles I
Introduce a special relationship with right triangles. Learners discover the ratio of the sides in a 30-60-90 triangle. After watching several examples and seeing two different methods, pupils find unknown sides in triangles. Scholars...
EngageNY
Prove the Pythagorean Theorem Using Similarity
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.
Curated OER
Special Right Triangles
Using the Pythagorean Theorem to solve for missing angles, students evaluate right triangles and their properties.
Radford University
Right Triangle Applications: Lessons 1 and 2
Use right triangles for more than just mathematical problems. The first two lessons of a unit ask pupils determine distances between cities by using the Pythagorean Theorem and a map. To cement understanding, learners use trigonometric...
Curated OER
Applying Special Right Triangles
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.
Shodor Education Foundation
Triangle Area
While the lesson plan focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can...
Curated OER
Trigonometry
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.
Curated OER
Geometry Chapter 7 Practice Test
In this geometry worksheet, 10th graders review problems that review a variety to topics relating to right triangles, including, but not limited to the Pythagorean Theorem, simplifying radicals, special right triangles, and right...
Curated OER
Special Right Triangles
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...
Curated OER
Special Right Triangles
In this special right triangles worksheet, 10th graders solve 9 different problems related to measuring various types of right triangles. First, they find the values of x and y in each right triangle shown. Then, students find the length...
Curated OER
Pythagorean Theorem and Special Right Triangles
Learners review the Pythagorean Theorem and apply it to word problems involving special right triangles.
Curated OER
Special Right Triangles
Students identify the different parts of a right triangle. In this geometry lesson, students use the Pythagorean Theorem to identify missing sides and angles of a right triangle. They work with irrational and rational roots.
Mathematics Vision Project
Module 7: Modeling with Geometry
Model good modeling practices. Young mathematicians first learn about cross sections and solids of revolution. They then turn their attention to special right triangles and to the Laws of Sine and Cosine.
Curated OER
Special Right Triangles
Students identify different types of special right triangles. In this geometry lesson plan, students differentiate between right triangles and isosceles triangles. they construct the triangles using geometry software and make conjectures...
Curated OER
Triangle Tango: Special Right Triangles
Young scholars investigate properties of special right triangles. In this geometry lesson, students use the Pythagorean Theorem to solve for missing angles and sides. They perform reflections.
EngageNY
The Definition of Sine, Cosine, and Tangent
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.
Curated OER
Solve Right Triangle
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.
Alabama Learning Exchange
"I Saw the Sine"
Discover trigonometric ratios that complement each other. Using two videos, the lesson introduces the trigonometric ratios. The class discovers the relationship between the sine and cosine of complementary angles.
Curated OER
Geometric Properties
Students find triangular angles using the angle theorem. In this geometry instructional activity, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.
CCSS Math Activities
Smarter Balanced Sample Items: High School Math – Claim 2
Problem solve across the content standards. The presentation slides provide 19 sample items from the Smarter Balanced high school assessment. Items illustrate Claim 2, problem solving, of the test and are drawn from all the high school...