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 about special right triangles.
Curated OER
Special Right Triangles
For this special right triangle worksheet, students use the trigonometric functions to determine angle measurement or the length of one side of a right triangle. This one-page worksheet contains 18 problems. Answers are provided at the...
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...
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...
Curated OER
Special Right Triangles Homework
In this geometry worksheet, students solve both kinds of special right triangles. There are 12 questions with multiple parts.
Curated OER
Special Right Triangles
Using the Pythagorean Theorem to solve for missing angles, young scholars evaluate right triangles and their properties.
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.
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
Special Right Triangles
In this special right triangles worksheet, students solve 15 short answer problems. Students use trigonometric functions to find missing side lengths of various right triangles.
Curated OER
Applying Special Right Triangles
In 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.
EngageNY
Special Triangles and the Unit Circle
Calculate exact trigonometric values using the angles of special right triangles. Beginning with a review of the unit circle and trigonometric functions, class members use their knowledge of special right triangles to find the value of...
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...
Shodor Education Foundation
Triangle Area
While the lesson 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 they...
Alabama Learning Exchange
Unit Circle: Special Angles—Just Know One
It's all about the patterns! Young scholars learn that the unit circle repeats itself in all four quadrants. Using these patterns, they evaluate the sine, cosine, and tangent of special angles.
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
Students review the Pythagorean Theorem and apply it to word problems involving special right triangles.
Curated OER
Special Right Triangles
In this special right triangles worksheet, 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...
Curated OER
Trigonometry Review Sheet
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...
Curated OER
A Special Relationship
Young scholars discover the relationships of the lengths of the sides of right triangles and right triangles using a series of drawings on dot paper. They investigate and solve problems of standard (customary and metric units) and...
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.
EngageNY
Sine and Cosine of Complementary Angles and Special Angles
Building trigonometric basics here will last a mathematical lifetime. Learners expand on the previous instructional activity in a 36-part series by examining relationships between the sine and cosine of complementary angles. They also...