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Worksheet
Curated OER

Countdown Challenge: Geometry Exploration

For Students 6th - 8th
In this geometry worksheet, students identify and draw right angles, acute angles, obtuse angles and straight angles. This one-page worksheet contains 34 problems.
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PPT
Curated OER

Classifying Triangles

For Teachers 5th - 7th
This presentation shows how triangles are classified by angle measurement and length of sides.  It reviews isosceles, scalene, obtuse, right, and acute classifications and includes questions for students to classify some of the triangles...
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Lesson Plan
Curated OER

Getting It Right! An Investigation of the Pythagorean Theorem

For Teachers 6th - 8th
Learners construct a variety of right triangles using a right-angled set square, cutting corners from pieces of paper or cardboard, and using dynamic geometry software. They measure the sides of these various right triangles and record...
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Worksheet
Curated OER

Properties and Attributes of Polygons

For Students 10th
In this geometry worksheet, 10th graders determine if a polygon is convex or concave and apply the polygon Angle sum theorem and the polygon exterior angle sum theorem to determine the measures of interior and exterior angles of a...
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Lesson Plan
Curated OER

Getting It Right!

For Teachers 6th - 8th
Students construct right triangles, measuring the sides and recording the measurements in spreadsheets. They analyze their measurements for patterns and research the Internet for information on Pythagoras.
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Lesson Plan
Curated OER

Measuring Angles

For Teachers 3rd
Third graders describe an amount of turn from a particular position to another using the 'circular' benchmarks of 0, ++, ++, ++, and full turn. Estimation language such as 'just about', 'between', 'not quite', 'just over', and similar...
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Lesson Plan
Curated OER

Sum of Interior/Exterior Angles with Wilbur

For Teachers 7th - 10th
Students identify the interior and exterior measures of polygons. In this geometry lesson, students identify the formula for interior angles of polygons. They differentiate between triangular and polygons angles.
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Interactive
Curated OER

Ten Multiple Choice Length Problems

For Students 9th - 10th
In this distance worksheet, students calculate the lengths of sides and diagonals of figures.  Students also compute lengths in shadow problems.  The solutions are provided by clicking on the "show answers" tab at the bottom of the page.
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Lesson Plan
Curated OER

Using Trigonometry

For Teachers 5th
Fifth graders explore the use of trigonometry to find unknown sides and angles in right-angled triangles, taking the concepts that were developed in the previous unit and looking at different ways of practicing the new skills. Students...
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Lesson Plan
Curated OER

Investigating the Idea of Tan

For Teachers 5th
Fifth graders use tan to solve problems involving right-angled triangles. They solve equations of the form tan(8) =a, for a between 180 degrees and 360 degrees. They state the value of tan (8) in special cases.
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Lesson Plan
West Contra Costa Unified School District

Pythagorean Theorem and Its Converse

For Teachers 9th - 12th Standards
Challenge scholars to prove the Pythagorean Theorem geometrically by using a cut-and-paste activity. They then must solve for the missing sides of right triangles.
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Lesson Plan
Curated OER

Investigating Segments in a Right Triangle

For Teachers 9th - 12th Standards
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
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Worksheet
Curated OER

Forty Mental Math Angle Problems

For Students 10th - 11th
In this angle worksheet, students answer forty mental math questions divided into four problem sets.  These problems require students to remember angle facts and so simple calculations mentally.