Curated OER
Trigonometric Ratios
Students measure and analyze angles. In this trigonometry instructional activity, students measure angles and distances use non-traditional techniques. They identify the different ratios of sine, cosine and tangent.
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Solving Right Triangles
Students 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 problem in which...
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Arithmetic and Geometric Sequences and Series
In this arithmetic and geometric sequences and series worksheet, 7th graders solve and complete 10 different sets of numbers. First, they determine the common difference in each set of numbers. Then, students subtract a pair of terms and...
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Special Right Triangles
In this special right triangles activity, 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 Pythagorean...
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Proportions
In this proportion worksheet, students identify equivalent fractions and solve proportions. This one-page worksheet contains ten problems.
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Using Trinonometry to Find Angle Measures
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.
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 problem.
Curated OER
The Laws of Sines and Cosines Made Simple!
Students study the law of sine and cosine. For this pre-calculus lesson, students create a triangle and identify the different ratios of a non-right triangle. They use the properties of sine and cosine to solve.
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Frame Yourself
Young ratio masters calculate and cut a frame (out of poster board) to accurately create an even frame around a picture of themselves. The frame needs to be proportional to the picture with constraints determined by the instructor.
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Understanding Fundamental Trigonometric Identities
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...
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Law of Sines
Students identify the ratios of a right triangle. In this calculus lesson plan, students use the law of sines to solve problems involving non-right triangles. They identify the different parts of a triangle.
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Investigating the Idea of Sin
Fifth graders use sin to solve problems involving right-angled triangles, Solve equations of the form sin(++) = a, for a between -180++ and 360++. They State and graph the value of sin(++) in special cases. They describe some of the ways...
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Right Triangle Stuff
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.
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Number of Solutions for a Triangle
In this solutions for a triangle learning exercise, learners use trigonometric ratios to determine the number of triangles that can be constructed with the given sides and angles. This one-page learning exercise contains 22 problems.
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...
Education Development Center
Similar Triangles
Model geometric concepts through a hands-on approach. Learners apply similar triangle relationships to solve for an unknown side length. Before they find the solution, they describe the transformation to help identify corresponding sides.
Curated OER
Trigonometric Applications Outside the Classroom
Fifth graders describe and demonstrate how trigonometry can be used to find the height of a tall building or tree. They describe and demonstrate how trigonometry can be used to find the height of a high hill, or other high object where...
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Math: Investigating Triangles
Tenth graders identify the trigonometric ratios for right angled triangles. Through independent investigation, they discover the constancy between the ratios of any two sides of similar triangles. In an alternative method, 10th graders...
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Geometry Exploration Basic Trig Functions
Tenth graders solve for missing sides on a triangle using the Pythagorean Theorem. In this geometry lesson, 10th graders are introduced to basic trigonometry functions as they solve problems of right triangles. They discuss the formulas...
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Applications of Triangles
Students apply the properties of a right triangle. In this triangle lesson, students describe and compare radians to degrees. They solve problems using the properties and ratios of a right triangle.
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Functions of Triangles
In this math worksheet, students find the functions for each of the triangles. Then they determine the reference angles from standard position.
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Simply Similar at Sea: Simple Triangles
Tenth graders answer a variety of problems based on similar triangle and learn about the rule of thumb. They will test the rule of thumb by estimating the distance to an object in the classroom.
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Hunter Fred's Quest for Dinner
Learners solve problems using trigonometric functions, specifically a problem about a tree stand. Pupils try to maximize the distance of hunting sight given certain restrictions. They use the Pythagorean Theorem, sine, cosine, and...
Curated OER
Unit Circle Lesson Plan
Students identify different locations on a unit circle. In this precalculus lesson, students identify the different trig properties and rewrite the equation of a circle in standard form. They use mnemonic devices to help them remember...