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Lesson Plan
Futures Channel

Folding Circles

For Teachers 7th - 12th Standards
Young scholars investigate properties of circles. For this geometry lesson, students differentiate between similarity and congruence as they observe polygons. They investigate properties of two and three dimensional shape.
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Interactive
CK-12 Foundation

Basic Trigonometric Functions: Ladder Length

For Students 9th - 12th Standards
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...
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Lesson Plan
Curated OER

Can a Geometric Mean be Nice?

For Teachers 11th - 12th
In this Geometry instructional (work)sheet, students are instructed on how to find the geometric mean.  Students are then shown how the geometric mean is applied to proving similar triangles.
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Worksheet
Curated OER

Mean Twisters - Mean Proportional

For Students 9th - 10th
For this mean proportional worksheet, students work in pairs to solve right triangle problems. They use ratios and proportions of similar triangles to determine a missing length. This two-page worksheet contains 16 problems.
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Worksheet
Curated OER

Similar Figures

For Students 7th - 9th
In this similar figures worksheet, students identify corresponding sides and corresponding angles of given polygons.  They identify similar figures.  This three-page worksheet contains 18 problems.
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Lesson Plan
Curated OER

Triangles with Collinear Circumcenters

For Teachers 9th - 10th
Pupils identify the circumcenter of a triangle. In this geometry lesson, students construct a perpendicular bisector using a straight edge and a compass. They differentiate between triangles and collinear points.
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Lesson Plan
Curated OER

Proportional Similarities

For Teachers 8th - 10th
Pupils model the geometric relationship with graphing. In this geometry lesson, students differentiate between parallel, perpendicular, similar and congruent shapes. They use properties of polygons to differentiate their shapes correctly.
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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, students differentiate between similar and congruent triangles. They use the Pythagorean Theorem to find the missing angles and sides.
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Lesson Plan
Curated OER

Math: Investigating Triangles

For Teachers 10th
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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Worksheet
Curated OER

Proportions 1

For Students 9th - 11th
For this proportion worksheet, students find the missing side of 4 shapes that are similar to their mate. Shapes include triangles and quadrilaterals,. In the second part of the worksheet, students use the scale factor to find missing...
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Lesson Plan
EngageNY

Trigonometry and the Pythagorean Theorem

For Students 9th - 11th Standards
Ancient Egyptians sure knew their trigonometry! Pupils learn how the pyramid architects applied right triangle trigonometry. When comparing the Pythagorean theorem to the trigonometric ratios, they learn an important connection that...
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Lesson Plan
Curated OER

Does Your Field Measure Up

For Teachers 9th - 11th
Students measure angles using a plane table kit. In this geometry lesson, students use trigonometric identities to find the values of the length of a football field.
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Lesson Plan
Curated OER

Dihedral Figures

For Teachers 6th - 12th
Middle and high schoolers perform transformations. In this web based lesson plan, learners explore dihedral figures. They use the web tools to translate, rotate, and reflect figures. Pupils identify lines of symmetry.
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Interactive
CK-12 Foundation

Identifying Sets of Pythagorean Triples: The iPad is a Pythagorean Triple

For Students 8th - 12th Standards
Compare iPad and HDTV aspect ratios. Individuals use the interactive to determine whether the measurements of screens represent a Pythagorean triple. The pupils determine what changes are needed to make a Pythagorean triple.
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Interactive
CK-12 Foundation

Secant, Cosecant, and Cotangent Functions: Hold the Ladder!

For Students 9th - 12th Standards
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...
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Interactive
Curated OER

Proportional Parts

For Students 9th - 10th
In this geometry instructional activity, 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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Lesson Plan
Curated OER

Amazing Consistent Ratios

For Teachers 7th - 9th
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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Lesson Plan
Curated OER

Altitude Locator

For Teachers 9th - 12th
Students use protractors, strings, and straws to construct a device used to determine the height of tall objects. In this applied geometry instructional activity, students use common objects to construct a tangent height guide. They use...
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Lesson Plan
Curated OER

Side Splitter Triangles

For Teachers 8th - 11th
Students investigate the side splitter theorem. In this geometry instructional activity, students estimate and solve problems dealing with ratios and proportions. They identify angles created by lines that are parallel.
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Worksheet
Curated OER

Area and Periemeter

For Students 10th
For 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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Lesson Plan
Curated OER

Soda Cans

For Teachers 8th - 10th
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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Lesson Plan
Curated OER

Pyramid in The Desert

For Teachers 9th - 11th
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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Lesson Plan
Curated OER

Scale Factor Area Perimeter

For Teachers 9th - 12th Standards
Mathematicians compare triangles at different scales. In this geometry instructional activity, learners calculate the area and perimeter of triangles. They use the Ti to make observation of the change that takes place as the triangles...
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Worksheet
Curated OER

Six Exercise Sets on Transformations

For Students 8th - 11th Standards
Middle and high schoolers solve fifteen problems from six exercise sets covering transformations, reflections, rotations, and enlargements. The solutions are provided.