CK-12 Foundation
Secant, Cosecant, and Cotangent Functions: Hold the Ladder!
Determine the length of a falling ladder. Pupils use an interactive to find the angle a ladder makes with the floor after it falls to answer questions. The scholars use the triangle formed in the interactive to determine values of...
Curated OER
Proportional Parts
In this geometry worksheet, students identify what makes triangles similar and congruent. They use SSS,SAS and AA to identify the correct ratio of each triangle. There are 15 questions.
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Introducing Trig
Fifth graders explore the importance of triangles in the real world. They find the unknown side of a right triangle using a scale drawing. Students use Pythagoras' Theorem and other appropriate ratios.
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Amazing Consistent Ratios
Students derive the six trigonometric identities. In 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.
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Altitude Locator
High schoolers use protractors, strings, and straws to construct a device used to determine the height of tall objects. In this applied geometry lesson, students use common objects to construct a tangent height guide. They use principles...
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Side Splitter Triangles
Students investigate the side splitter theorem. In this geometry lesson plan, students estimate and solve problems dealing with ratios and proportions. They identify angles created by lines that are parallel.
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Scaling Figures Two
In this similar figures activity, students find the missing side of the larger figure when the smaller figure's sides are given. Students complete 4 problems.
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Area and Periemeter
In this geometry worksheet, 10th graders determine the area and perimeters of various quadrilaterals and triangles. The one page worksheet contains ten problems. Answers are not provided.
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Math Hw #15: Proportions
In this proportions worksheet, students solve 8 word problems. Students determine the cost of an item given a unit cost. Students find a missing side length of a triangle using proportions of similar triangles.
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Symmetry and Geometric Shapes on Campus
Build on your learners' previous knowledge of geometric shapes and symmetrical figures. Then set them out to take photos of geometric shapes on campus. They assess whether the photos contain symmetry or not.
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Soda Cans
Students identify and use properties of similar figures. In this geometry lesson, students use proportions of the sides of triangles to solve triangular relationships. They use soda can as their visuals.
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Pyramid in The Desert
Students investigate the Sierpinski triangle and calculate the ratio and area of the triangle. In this fractals lesson, students calculate parts of a Sierpincki triangle. They use Google Earth to help them construct the different parts...
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Introduction to Fractals: Geometric Fractals
Middle schoolers study and observe the patterns made by the areas of the Sierpinski Triangle. Students use the computer to draw two or three iterations to discover the number patterns. Middle schoolers complete worksheets based on...
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Scale Factor Area Perimeter
Mathematicians compare triangles at different scales. In this geometry lesson, students calculate the area and perimeter of triangles. They use the Ti to make observation of the change that takes place as the triangles are dilated.
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Six Exercise Sets on Transformations
Middle and high schoolers solve fifteen problems from six exercise sets covering transformations, reflections, rotations, and enlargements. The solutions are provided.
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Trig River
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.
West Contra Costa Unified School District
Introduction to Trigonometric Functions
Scholars first learn the definitions of the sine ratio, the cosine ratio, and the tangent ratio. After mastering these definitions, they use the new information to solve triangles.
EngageNY
The Scaling Principle for Area
As they investigate scaling figures and calculate the resulting areas, groups determine the area of similar figures. They continue to investigate the results when the vertical and horizontal scales are not equal.
EngageNY
Scale Factors
Is it bigger, or is it smaller—or maybe it's the same size? Individuals learn to describe enlargements and reductions and quantify the result. Lesson five in the series connects the creation of a dilated image to the result. Pupils...
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THE MEAN INDEX CARD
Learners cut an index card to create three similar right triangles and explore the congruencies and proportions that exist. They investigate the properties of lines and concepts of congruency, similarity, tangency and symmetry of...
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As the Bird Flies
Young scholars investigate the properties of lines and congruent triangle theorems as well as apply geometric properties and relationships to real-world mathematical problems. Given two different scenarios, they examine maps that have...
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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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Recursion on a Calculator
In this math worksheet, students investigate repeated values on the calculator. They also read the explanation of the golden triangle and its proof.
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Understanding Fundamental Trigonometric Identities
Students 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 review...