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Lesson Plan
Curated OER

Similar Triangles and Proportions

For Teachers 9th - 12th Standards
Pupils investigate similar triangles and proportions as they make conjectures about the length of sides of similar triangles. For this lesson, have your class construct similar triangles using Cabri Jr so that they share a common vertex.
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Lesson Plan
Curated OER

Triangle Inequality Theorem

For Teachers 9th - 12th Standards
High schoolers investigate the relationship between angle measures and sides of a triangle and the relationships among the three sides of a triangle. The use of technology (Cabri, Jr.) allows learners to make and test conjectures as they...
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Lesson Plan
Curated OER

Triangles: Triangle Inequalities

For Teachers 9th - 12th Standards
Using SketchPad on their calculators to construct triangles, young scholars measure exterior angles and remote interior angles of their constructed triangle. Students develop the triangle inequality from observation and exploration with...
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Lesson Plan
Curated OER

Triangle Classificaition with Geometer's Sketchpad.

For Teachers 7th - 12th
Students use Geometer's Sketchpad to draw triangles and explore the classificaiton of each using the mearsures of interior angles and the lengths of the sides.
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Lesson Plan
Curated OER

Exploring the Orthocenter of a Triangle

For Teachers 9th - 12th Standards
Young mathematicians explore the concept of triangles as they construct altitudes of triangles to find the orthocenter. Learners construct their triangles using Cabri Jr. on their graphing calculators and find that the altitudes of a...
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Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles worksheet, 10th graders solve and complete 5 various types of problems. First, they solve each of the triangles shown and find the area of each triangle. Then, students find the perimeter and area of the regular...
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Worksheet
Curated OER

Determine the Measure of an Angle of a Right Triangle.

For Students 10th - 11th
In this geometry worksheet, students solve word problems by finding the values of missing angles and missing sides of triangles. They review their trigonometric properties of a right triangle. There are 9 problems with an answer key.
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Lesson Plan
Curated OER

Sum of Angles on a Triangle

For Teachers 4th - 5th
Use this lesson for a basic review of angles. While the activities discussed are outlined, there are no materials provided to make implementation possible. When using this resource, it is necessary to create worksheets and other...
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Lesson Plan
Curated OER

Geometric Properties

For Teachers 9th - 12th
Students find triangular angles using the angle theorem. In this geometry lesson, students describe labeled triangles, use the pythagorean theorem, and rewrite information about triangles in standard form.
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Interactive
CK-12 Foundation

Ambiguous Case: Furniture Store Problems

For Students 10th - 12th
Remove any ambiguity about using a helpful resource. Individuals use an interactive to find the number of triangles that fit given conditions. They find that some conditions can result in more than one triangle in the ambiguous case.
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Instructional Video24:21
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Flipped Math

Intro to Trigonometry

For Students 9th - 12th Standards
Expand trigonometric ratios beyond right triangles. Pupils start with a review of trigonometric ratios and then take a look at angles in standard position to determine their measurements. Scholars discover how to find coterminal angles...
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Interactive
CK-12 Foundation

Angles of Elevation and Depression: Fly-By Calibration

For Students 9th - 12th Standards
Determine the distance between two trees from afar. Pupils use an interactive resource to create two right triangles using trees and a plane. They determine the horizontal legs of each triangle to find the distance between the two trees.
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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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Worksheet
Curated OER

2-Dimensional Shapes: Drawing Shapes

For Students 2nd - 3rd Standards
Some of the best practice with shape identification comes from drawing the figures first-hand. Young geometers draw nine two-dimensional shapes: rectangle, circle, square, pentagon, hexagon, octagon, triangle with three equal sides,...
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Worksheet
Curated OER

Naming Polygons

For Students 3rd - 4th Standards
What polygon is this? Young geometers categorize shapes by circling all the quadrilaterals in a set of figures. Next, they write the names of 10 polygons using a visual guide as reference. Review the guide together before they start if...
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Lesson Plan
Curated OER

Worksheet 7: Slope and Tangents

For Teachers 12th - Higher Ed
Providing both review and practice problems, this worksheet prompts students to answer five questions having to do with slope, tangents lines, graphing, the Squeeze Theorem, differentiable functions and derivatives. This activity could...
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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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Worksheet
Curated OER

Academic Grade 9 Assessment of Mathematics: Algebra I and Geometry

For Students 9th - 10th
Test your class, or use this 12 page math packet as chapter review. They solve 21 multiple choice problems which require them to graph linear equations, find the volume of prisms and cones, find unknown angles, and determine...
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PPT
Curated OER

Math - Blank Jeopardy

For Teachers 8th - 9th
Double Jeopardy! Review polynomials, statistics, triangles, graphing, mode, median, mean, measurement, slope, distance, and ratio.  Note: Have everyone use a white board to do the problems to get a quick check on understanding.
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PPT
Curated OER

The Shape Song

For Teachers Pre-K - 2nd
As a review of geometric shapes, such as circles, triangles, and squares, this resource would be a terrific addition to a classroom lesson. The visuals are inviting and the number of sides to each figure are also identified. In addition,...
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PPT
Curated OER

Who Wants to Be a Champion: Perimeter, Area, Symmetry

For Teachers 3rd - 5th
Have your learners practice finding the perimeter and area of geometric shapes using this resource. While just a simple review, this could be a wonderful way to solidify the concepts in their minds.
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Worksheet
Curated OER

Triangle Review

For Students 4th - 6th
In this triangle worksheet, students draw the type of triangles described, 4 total. Space is provided for student's drawings. A reference web site is given for additional activities.
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Worksheet
Curated OER

Right Triangles

For Students 10th
For 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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Worksheet
Curated OER

Triangles

For Students 10th
In this triangles instructional activity, 10th graders solve and complete 2 different problems. First, they find the perimeter of each triangle as described. Then, students find the slope of each side and altitude to each side of the...