Curated OER
Right Triangles and The Unit Circle
Students solve right triangles using trigonometry. In this geometry lesson, students use the unit circle to identify different trig values. They identify the six trigonometric identities.
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...
EngageNY
Incredibly Useful Ratios
Start the exploration of trigonometry off right! Pupils build on their understanding of similarity in this lesson that introduces the three trigonometric ratios. They first learn to identify opposite and adjacent...
Illustrative Mathematics
Two Wheels and a Belt
Geometry gets an engineering treatment in an exercise involving a belt wrapped around two wheels of different dimensions. Along with the wheels, this belt problem connects concepts of right triangles, tangent lines, arc length, and...
Curated OER
Trigonometry Ratios in Right Triangles
In this trigonometry ratios in right triangles learning exercise, 10th graders solve 10 different trigonometric ratios that apply to right triangles. First, they define a trigonometric ratio and its three most common ratios, sine,...
Curated OER
Solving Right Triangles
Young scholars investigate the basic trigonometric functions. In this geometry/trigonometry lesson, students explore strategies to solve right triangles using basic trigonometric functions. The lesson includes an application...
Curated OER
Right Triangles and The Pythagorean Theorem
Pupils play a game to reinforce concepts of the Pythagorean Theorem. In this geometry lesson, students find the missing angle and lengths of a right triangle. They use properties of trigonometry about sine, cosine and tangent to solve...
Curated OER
Trigonometry Ratios
High schoolers identify the different angles and sides of a triangle. For this geometry lesson, students identify the six trigonometric ratios. They graph the graph of each trig function and analyze it.
CK-12 Foundation
Unit Circle: Medieval Castle Defense
Who needs a plan — let trigonometry protect you! Pupils determine the angle of an approaching enemy to a village wall. The scholars determine the exact value of trigonometric functions for the angle. Class members use trigonometry to...
CK-12 Foundation
Basic Trigonometric Functions: Ladder Length
Climb the ladder to trigonometry. The interactive introduces trigonometric ratios and finding lengths of sides of right triangles created by a ladder and a building. Learners use the interactive to create triangles by moving the top of...
Flipped Math
Trig Ratios
Take ratios of sides to a new level. Pupils learn the definitions of the three basic trigonometric ratios in right triangles. Using the definitions, scholars find missing lengths in right triangles, based on a known angle. Individuals...
CK-12 Foundation
Sine, Cosine, and Tangent Functions: Lighthouse
How far is that boat from the lighthouse? Scholars create diagrams to represent a scenario given the angle of depreciation from a lighthouse to a boat. Learners apply the basic trigonometric functions to find various distances...
Curated OER
Inverse Functions in Trigonometry
In this inverse functions in trigonometry activity, students find the missing angles in eight right triangles, given the length of two sides.
Illustrative Mathematics
Finding Trig Values
Let's keep trigonometry simple. When given a cosine ratio, learners must use the clues about the quadrant to determine the sine and tangent ratios. The answer key has a complete worked-out solution to help guide pupils through the...
Mathematics Assessment Project
Hopewell Geometry
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...
Texas Instruments
What's the Trig?
Learners determine the trigonometric relationships within a triangle as they construct a right triangle on the Ti-89. They find the sine, cosine, and tangent of various angles of their triangle construction.
Curated OER
Right Triangles and Unit Circles
Students evaluate the six trigonometric values of a trig function. In this trigonometry lesson plan, students use the Unit Circle to find the values of right triangles and their angles. They identify an angle of elevation and...
Curated OER
Getting it Right!
Students investigate error. As shown in earlier activities from navigation lessons 1 through 3, without an understanding of how errors can affect position, one cannot navigate well. Students explore how computers can help in navigation....
Curated OER
Section 8-6: Solving Problems Using Trigonometric Ratios
In this trigonometric ratios worksheet, high schoolers solve 20 short answer and multiple choice problems. Students use trigonometric ratios, the angle of depression, and angle of elevation to find missing side lengths of angles of...
Center for Innovation in Mathematics Teaching
Trigonometry
This unit covers the basic trigonometry including understanding radians, how to convert between radians and degrees, the area of a circle subtended by an angle, basic properties and graphs of sine, cosine, tangent, and solving...
EngageNY
Complex Numbers and Transformations
Your learners combine their knowledge of real and imaginary numbers and matrices in an activity containing thirty lessons, two assessments (mid-module and end module), and their corresponding rubrics. Centered on complex numbers and...
Inside Mathematics
Hopewell Geometry
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...
Curated OER
Introducing Trigonometry
Eleventh graders explore the three basic trigonometric functions. In this trigonometry/Algebra II activity, 11th graders use GeoGebra and the unit circle to define the ratios of sides is a right triangles as they examine the full domain...
Curated OER
Finding the Area of an Equilateral Triangle
The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...