Lesson Plan
Curated OER

Inequalities and Triangles

For Teachers 9th - 10th
Students prove and apply theorems of triangle inequality and hinge theorem. In this geometry lesson, students will discuss which triangle is bigger and why. They will use theorems, such as Exterior Angle Inequality or the Pythagorean...
Worksheet
Curated OER

Similar Figures

For Students 7th - 10th
In this similar figure worksheet, learners find the length of a missing side of given triangles and quadrilaterals.  This six-page worksheet contains 24 problems.  Answers are provided on the last page.
Worksheet
Curated OER

A Different Proof of the Law of Cosines

For Students 9th - 12th
In this proofs worksheet, learners construct 1 proof of the law of cosines.  Students construct a right triangle within a circle to  prove the law of cosines.
Worksheet
Curated OER

Geometric Figure Quiz

For Students 9th - 12th
In this geometric figure worksheet, students answer 10 multiple choice questions about geometric figures.  Students find missing angles, interior angles, properties of polygons, etc.
Worksheet
Curated OER

Perimeter of Triangle Worksheet

For Students 7th - 8th
In this perimeter worksheet, students find the perimeter of given triangles.  This two-page worksheet contains 6 problems.  Answers are provided on the last page.
Worksheet
Curated OER

Area of Triangles 2

For Students 9th - 12th
In this area of triangles worksheet, students solve 18 area of triangles problems.  Students find the area of various types of triangles given a graph of the triangle.
Worksheet
Curated OER

Area of Right Triangles

For Students 8th - 10th
In this are of right triangles worksheet, students read graphs and explore congruent triangles.  They find the area of rectangles and of right triangles.  This one-page worksheet contains explanations, instructions, and 8...
Worksheet
Raytheon

Understanding Triangles

For Students 6th - 8th
In this understanding triangles worksheet, learners read 6 pages of examples and explanations about identifying triangles, determining length of sides and degrees of angles, including the hypotenuse, then answer 28 questions, answers...
Worksheet
Curated OER

Find the Side of the Triangle

For Students 9th - 10th
In this geometry worksheet, students investigate the missing side of  triangles given the other two sides. There are 5 questions with a solution key.
Lesson Plan
Curated OER

Geometric Shapes

For Teachers 5th - 7th
Students identify polygons.  In this geometric shape activity, students explore the characteristics of polygons.  They identify polygons, and classify triangles according to their sides and angles.  Students create a...
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. ...
Lesson Plan
Curated OER

30-60-90 Right Triangles in Cabri Jr.

For Teachers 9th - 12th Standards
Young mathematicians draw and label right triangles using Cabri Jr. technology. They create other special right triangles and identify the length of the hypotenuse and each leg. High schoolers explore the ratios to determine how the...
Lesson Plan
Curated OER

Algebra/Geometry Institute Summer 2009 - Triangles and the Pythagorean Theorem

For Teachers 7th
Seventh graders find the perimeter and area of triangles.  In this finding the perimeter and area of triangles lesson, 7th graders find the perimeter and area of triangles given two sides.  Students find the missing side by...
Lesson Plan
Curated OER

Pythagorean Theorem: Algebra/Geometry Institute Summer 2010

For Teachers 7th - 9th
Students solve Pythagorean theorem problems.  in this Pythagorean theorem lesson, students read real world problems, draw diagrams, and then solve with the Pythagorean theorem.  They define hypotenuse and leg.  students...
Lesson Plan
Curated OER

Basic Shapes

For Teachers 11th - 12th
Students create books about shapes.  In this shape lesson, students select a topic such as points, lines, angles, planes, polygons, quadrilaterals, triangles, circles, and polyhedra.  In groups, they create an illustrated...
Lesson Plan
Curated OER

Shape Up

For Teachers 6th - 8th
Students explore differents types of triangles and quadriaterals. In this polygon instructional activity, students  model identify and compare two and three dimensional geometric figures. Students create tangrams and discover the...
Lesson Plan
Texas Instruments

Getting Started with Cabri Jr.

For Teachers 9th - 12th Standards
Pupils construct geometric figures using Cabri Jr. in this constructing geometric figures using Cabri Jr. lesson. They familiarize themselves with Cabri Jr. and construct segments and triangles. Your learners will use various tools to...
Lesson Plan
Curated OER

Areas of States - Estimation

For Teachers K - 8th
Students estimate the area of states using the formulas for the areas of rectangles, squares, and triangles. In this geometric shapes lesson, students divide irregular shaped states into shapes. They use the formulas for areas of...
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.
Worksheet
Curated OER

Polygons

For Students 6th - 10th
In this polygons instructional activity, students read about and complete many activities involving triangles, angles, and symmetry. Students complete 17 pages of activities.
Lesson Plan
Curated OER

Circumscribing a Circle About a Triangle

For Teachers 9th - 12th Standards
Pupils circumscribe a circle about a triangle. They construct a triangle using Cabri Jr and then circumscribe it. They then use knowledge of perpendicular bisectors and circumcenters to locate the center of the circle and then...
Lesson Plan
Curated OER

Exploring the Circumcenter of a Triangle

For Teachers 9th - 12th Standards
Students construct the circumcenter of a triangle. In this constructing the circumcenter of a triangle lesson plan, students construct a triangle using Cabri Jr. Students draw perpendicular bisectors of the sides of the triangle....
Lesson Plan
Curated OER

Investigating Area Relationships

For Teachers 9th - 12th Standards
Learners investigate the area of various figures. They construct triangles and quadrilaterals using Cabri Jr. and discuss the relationships between different angles, side lengths, and figures.
Lesson Plan
Curated OER

Investigating Segments in a Triangle

For Teachers 9th - 12th Standards
Pupils investigate segments in a triangle by constructing a triangle using Cabri Jr. They construct segments within the triangle that lie on the midpoints of the triangle's sides. Learners then compare the slope of base of the triangle...