Lesson Plan
Curated OER

Understanding Fundamental Trigonometric Identities

For Teachers 9th - 12th
Young scholars are introduced to the basic trigonometric identities. Using a diagram, they discover why the parts of the unit circle as named as they are and use equations to finalize the Pythagorean trigonometric identities. They also...
Worksheet
Curated OER

Using Trinonometry to Find Angle Measures

For Students 10th - 12th
In this trigonometric ratios worksheet, students find the missing angle of 20 triangles by using sine, cosine and tangent ratios. Students compute the angle measurement of given ratios for six problems.
Worksheet
Curated OER

Geometry Involving Figures - Week 12 (Ratio and Surface Area)

For Students 10th - 12th
In this ratio and surface area activity, students find the ratio of surface area of one figure to another. They determine the length of sides and angles through similar figures. Students use trigonometric ratios to find the length of...
Lesson Plan
Curated OER

Solve Right Triangle

For Teachers 9th - 11th
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.
Lesson Plan
Curated OER

Length of an Arc and Area of a Sector

For Teachers 10th
In this length of an arc and area of a sector worksheet, 10th graders solve and complete 12 different types of problems. First, they find the length of an arc in a circle with a given radius and central angle measure. Then, students find...
Worksheet
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Curated OER

Trigonometry and the Calculator

For Students 10th
In this geometry worksheet, 10th graders use a graphing calculator to evaluate trigonometric functions and their inverses. The four page worksheet contains explanation, examples, and twenty questions. Answers are not...
Worksheet
Curated OER

Trigonometry

For Students 10th - 12th
In this right triangles worksheet, students use trigonometric ratios to determine the length of a side of a triangle or a missing angle measurement.  This two-page worksheet contains 20 problems.
Lesson Plan
Curated OER

Exploring Trigonometric Ratios

For Teachers 10th - 12th
Students calculate the different ratios using a right triangle. In this trigonometry lesson, students identify the sine, cosine and tangent of each side. They find the missing angles using the different ratios.
Lesson Plan
Curated OER

Investigating Trigonometric Ratios Through Similar Right Triangles

For Teachers 9th - 10th
Students identify similar and congruent right triangles. In this geometry lesson, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.
Worksheet
Curated OER

Right Triangle Stuff

For Students 12th - Higher Ed
In this right triangle activity, students use trigonometric ratios to find the hypotenuse, right angle, opposite leg and angles. This one-page activity contains eight problems. Answers are provided at the bottom of the page.
Worksheet
Curated OER

Law of Sines

For Students 10th - 12th
In this Law of Sines worksheet, learners use trigonometric ratios to determine angle measurement and/or the length of the side of a triangle. This one-page worksheet contains ten trigonometric ratio problems.
Worksheet
Curated OER

Number of Solutions for a Triangle

For Students 11th - Higher Ed
In this solutions for a triangle worksheet, students use trigonometric ratios to determine the number of triangles that can be constructed with the given sides and angles. This one-page worksheet contains 22 problems.
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...
Lesson Plan
Curated OER

Exploring Trigonometric Ratios

For Teachers 9th - 10th
Students identify the ratios of trig functions. In this trigonometry instructional activity, students construct triangles and use it to derive the values of sine, cosine and tangent. They use Cabri software to create the visual of the...
Lesson Plan
Curated OER

Amazing Consistent Ratios

For Teachers 7th - 9th
Learners derive the six trigonometric identities. For this trigonometry lesson, students find the ratios of sine, cosine and tangent using the right triangle. They use properties of the Pythagorean Theorem to find the trig identities.
Worksheet
Curated OER

The Sine and Cosine Ratios

For Students 10th
In this geometry worksheet, 10th graders write the ratio that represents the sine and cosine of the indicated angle.  The one page worksheet contains two multiple choice questions.  Answers are included. 
Lesson Plan
EngageNY

An Area Formula for Triangles

For Teachers 11th - 12th Standards
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
Lesson Plan
Curated OER

Trig River

For Teachers 6th - 8th
Students calcute distances using trigonometry and angle measurements. They estimate the width of the Trig River, measure it and compare their results with their classmates. They collaborate with a group to research and find the results.
Interactive
Curated OER

Tangents

For Students 10th - 12th
In this tangents learning exercise, students use tangent ratios to find the length of the sides of right triangles. This one-page learning exercise contains 10 multi-step problems.  Answers are provided.
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 plan, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.
Lesson Plan
Curated OER

Trigometric Ratios

For Teachers Pre-K - 6th
This lesson plan requires a worksheet that is not connected. It is integral to the lesson plan.
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...
Lesson Plan
Curated OER

Introducing Trigonometry

For Teachers 11th
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...
Lesson Plan
Curated OER

Solving Right Triangles

For Teachers 10th - 11th
Students investigate the basic trigonometric functions.  In this geometry/trigonometry instructional activity, students explore strategies to solve right triangles using basic trigonometric functions.  The instructional...