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Lesson Plan
Curated OER

Finding the Area of an Equilateral Triangle

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

Learning Unit: The Pythagorean Theorem

For Teachers 8th - 10th
Middle and high schoolers research the life of Pythagoras and the Pythagorean theorem. They write a short biography of Pythagoras and learn to apply the theorem in their study of right triangles.
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Lesson Plan
Curated OER

Principles of Square Roots Lesson Plan

For Teachers 8th - 11th
Middle and high schoolers investigate all the different places in math that square root is present. In this geometry lesson, pupils discuss square roots as it relates to a right triangle and construction. They go over altitude, rise,...
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Lesson Plan
Curated OER

Flying with Pythagoras

For Teachers 7th - 10th
A lengthy narrative about Pythagoras and his students precedes an activity in which your young mathematicians practice using the Pythagorean theorem to solve three problems about flight and distance. Answers are provided. 
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Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 7th - 10th
In this measurement lesson, learners examine the Pythagorean Theorem, perimeter, and areas of right triangles. They record their measurements and research their findings on a grid.
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Lesson Plan
Curated OER

You Can't Go Wrong with a Right Triangle 2

For Teachers 3rd - 5th
Upper graders use the properties of right angle trignonmetry to measure objects such as the school flagpole. They solve real world problems using these properties.
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Lesson Plan
Curated OER

Squares, Rectangles, and Right Triangles

For Teachers 3rd - 5th
Youngsters identify and draw polygons including squares, rectangles, and right triangles. In this polygons lesson plan, everyone draws these shapes that have right angles in their math journals.
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Worksheet
Curated OER

Learning About Triangles

For Students 4th - 6th
Upper graders label four triangles and fill in the labels correctly. They draw three original triangles and answer the questions about them.
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Worksheet
Curated OER

Types of Triangles

For Students 2nd - 4th
Young math whizzes solve four problems in which a triangle with labeled angle measurements is analyzed. They mark if each triangle is acute, right, or obtuse.
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Lesson Plan
Curated OER

Acute Triangles

For Teachers 4th - 8th
Learners study acute triangles. They measure angles using a protractor, then classify the triangles as either right, obtuse, or acute. Everyone creates a design for a Navajo rug using only acute triangles.
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Lesson Plan
Curated OER

A Special Relationship

For Teachers 6th - 8th
Young scholars discover the relationships of the lengths of the sides of right triangles and right triangles using a series of drawings on dot paper. They investigate and solve problems of standard (customary and metric units) and...
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Lesson Plan
Curated OER

Special Right Triangles

For Teachers 10th - 12th
For this special right triangle worksheet, students use the trigonometric functions to determine angle measurement or the length of one side of a right triangle. This one-page worksheet contains 18 problems. Answers are provided at the...
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Lesson Plan
Curated OER

Finding the Area and Perimeter of Polygons

For Teachers 7th
Seventh graders practice finding the area and perimeter of polygons. In this polygon area lesson, 7th graders brainstorm shapes and take a walk to locate shapes. Students record properties of shapes and use various shapes to make a...
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Worksheet
Curated OER

Easy Worksheet: Trigonometry

For Students 9th - 12th
In this trigonometry worksheet, students solve 4 short answer problems. Students find the sine, cosecant, secant or cotangent of an angle given a diagram of a right triangle with various measurements labeled.
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Worksheet
Curated OER

Easy Worksheet: Right Triangles and Circles

For Students 9th - 12th
In this right triangles and circles activity, high schoolers solve 4 short answer problems. Students describe a right triangle formed by point on a circle and an angle measure.
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Worksheet
Curated OER

Special Right Triangles

For Students 9th - 12th
In this special right triangles worksheet, students solve 15 short answer problems. Students use trigonometric functions to find missing side lengths of various right triangles.
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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.
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Lesson Plan
Curated OER

Trigonometric Functions of Acute Right Triangles

For Teachers 9th - 11th
Students derive the six trigonometric functions. In this trigonometry activity, students show their understanding of trigonometric functions as they relate the right triangles. They find the missing angles and side use trig ratios of...
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Lesson Plan
Curated OER

Pythagorean Theorem

For Teachers 7th - 8th
Students discover the Pythagorean Theorem.  In this discovering the Pythagorean Theorem lesson, students measure the lengths of various triangles to the nearest centimeter. Students record their measurements in a table.  Students square...
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Lesson Plan
Texas Instruments

What's the Trig?

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

Ratios in Right Triangles

For Teachers 9th - 12th Standards
Learners calculate the sides of right triangles in this trigonometric ratios lesson. They use Cabri Jr. software and TI-83 or TI-84 calculators to find the side lengths and their ratios to each other for various triangles. The provided...
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Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve and complete 13 different problems. First, they find the lengths of both missing sides. Then, students find the altitude of an equilateral triangle given the measure of one side. They...
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Worksheet
Curated OER

Circles

For Students 10th
In this circles worksheet, 10th graders solve and complete 13 various types of problems. First, they solve each set of triangles for the given variable. Then, students name a radius, a diameter, a tangent, a secant, a point of tangency,...
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Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve and complete 12 various types of problems. First, they solve for x given each of the right triangles shown. Then, students determine the length of the shorter diagonal given the...