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Lesson Plan
Curated OER

Right Triangle Geometry

For Teachers 9th - 11th
Students study the basic principles of right triangle geometry needed to solve for unknown values of a right triangle. They apply and master the principles of right triangle geometry by solving problems.
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Lesson Plan
Curated OER

Drawing a Triangle with Cabri Junior

For Teachers 9th - 12th Standards
Learners draw triangles on their graphing calculators using the Cabri Junior application. In this graphing calculator lesson, students follow step by step directions to create triangles on their calculator. They identify the type of...
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Worksheet
Curated OER

More Congruent Triangles

For Students 10th
In this congruent triangles worksheet, 10th graders solve 5 various types of geometry problems related to triangles. First, they draw and label triangles, indicating the additional pairs of corresponding parts that would have to be...
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Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve and complete 12 different types of problems. First, they solve for a variable given each of the right triangles with the sides as indicated. Then, students determine the shorter...
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Organizer
Curated OER

Types of Triangles

For Students 9th - 10th
As a reference sheet for types of triangles, this worksheet would be good for students to keep in their binder or to take notes about; however, it would need to accompany an existing lesson as there is no activity beyond basic...
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Worksheet
Curated OER

Identifying Similar Triangles

For Students 10th
In this identifying similar triangles worksheet, 10th graders solve 6 different types of problem that include identifying and comparing similar triangles. First, they identify the three ways that determine whether two triangles are...
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Lesson Plan
Curated OER

Concurrent Lines in Triangles

For Teachers 9th - 12th
Students explore the concept of concurrent lines in triangles. In this concurrent lines in triangles lesson, students work in groups to investigate properties of concurrent lines in acute, right, and obtuse triangles. Students use a...
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Lesson Plan
Curated OER

Types of Triangles

For Teachers 5th
Fifth graders explore the required functions of the Geometer's Sketchpad. Using the computer software, they construct similar triangles and identify them by angles and sides. Students classify triangles. Afterward, they complete problems...
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Worksheet
Curated OER

Sum of Angles

For Students 6th
In this sum of angles worksheet, 6th graders solve and complete 6 different types of problems. First, they identify different alternate and corresponding angles. Then, students state what the angles of a triangle add up to and how they...
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Lesson Plan
Curated OER

Congruent Triangles Postulates

For Teachers 3rd - 4th
Students discover three lettered postulates that prove triangles congruent.
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Worksheet
Curated OER

Special Segments in Triangles

For Students 10th
In this special segments in triangles worksheet, 10th graders solve 6 various types of problems related to determining types of segments found in triangles. First, they find a segment if the line parallel is a median or an altitude....
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Worksheet
Curated OER

Interior and Exterior Angles

For Students 10th
In this interior and exterior angles worksheet, 10th graders solve 10 different problems that include determining the interior and exterior of various triangles. They determine the measure of an exterior angle and then they determining...
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Worksheet
Curated OER

Triangle Inequalities

For Students 10th
In this triangle inequalities worksheet, 10th graders solve 10 different problems that include various types of triangles. First, they determine which side is the longest side of a triangle with given the exterior angle measurement....
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Lesson Plan
Curated OER

8th Grade Math Classifying Triangles and Quadrilaterals

For Teachers 8th
Eighth graders engage in a lesson that is about classifying polygons with the focus being upon specific triangles and quadrilaterals. They conduct activities using cutouts for kinesthetic learners to help make connections while...
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Worksheet
Curated OER

Family Activity: Triangles and Quadrilaterals

For Students 6th - 8th
In this triangles and quadrilaterals worksheet, students solve 7 short answer problems. Kids find objects around the house that are constructed from triangles, parallelograms, trapezoids, squares, rectangles. Students sketch the object...
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Worksheet
Curated OER

Triangles Word Search

For Students 5th - 6th
In this word search worksheet, students locate 7 types of triangles. Triangles include isosceles, acute, equilateral, right, and obtuse.
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Lesson Plan
Curated OER

Triangles in Architecture

For Teachers 10th - 12th
Learners find triangles in the real world. In this geometry lesson, students analyze and identify properties of two and three-dimensional objects. They differentiate between similarity and congruence.
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Lesson Plan
Houghton Mifflin Harcourt

Introducing the Concept: Triangles and Quadrilaterals

For Teachers 5th - 7th Standards
Guide your geometers through the process of constructing polygons. They learn how to draw triangles, squares, parallelograms, rectangles, rhombuses, and trapezoids with specified angles using a protractor and a ruler. The lesson plan...
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Worksheet
Curated OER

8th Grade Math Worksheet

For Students 8th
In this linear equations instructional activity, 8th graders solve 10 different problems that include various types of linear equations. First, they write the distance between Venus and the Sun in scientific notation. Then, students...
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Lesson Plan
Houghton Mifflin Harcourt

Developing the Concept: Triangles and Quadrilaterals

For Teachers 5th - 7th Standards
Exact narrative and examples make this lesson on polygons easy to implement. Through it, your class will learn how to use a protractor and ruler to construct triangles and quadrilaterals according to your directions. Your class will be...
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Lesson Plan
Improving Measurement and Geometry in Elementary Schools

The Sum of the Interior Angles of a Polygon

For Teachers 4th - 5th Standards
Junior geometers discover that polygons can be decomposed into triangles and that the number of triangles can be determined by a rule. Note that the Geometer’s Sketchpad® software is required to carry out all components of this...
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Lesson Plan
Curated OER

Triangles and Things

For Teachers K - 2nd Standards
Young learners listen to the story book The Greedy Triangle as the teacher introduces new polygon shapes. They use geometric stencils to trace a quadrilateral, a pentagon, a hexagon, and an octogon onto a foldable notepad. They identify...
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Interactive
Curated OER

Angles in a Triangle

For Students 10th
In this geometry learning exercise, 10th graders determine the measure or measures of the missing angle(s) in a triangle. The one page interactive learning exercise contains four questions. Answers and hints are included. 
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Worksheet
Curated OER

Triangle Review

For Students 5th - 6th
In this triangle review instructional activity, students define what type of triangle is being described, then draw a picture of it. A reference web site is given for additional activities.