Lesson Plan
Curated OER

Congruent Triangles

For Teachers 9th - 12th Standards
Students identify properties of triangles. In this geometry lesson, students differentiate between similar and congruent triangles. They use the umber of sides to help define the angle of the polygon.
Worksheet
Curated OER

Area of Quadrilaterals

For Students 10th
In this area of quadrilaterals 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 prove that the sum of the squares of...
Lesson Plan
Curated OER

Special Right Triangles

For Teachers 9th - 12th Standards
Using the Pythagorean Theorem to solve for missing angles, students evaluate right triangles and their properties.
Lesson Plan
Arizona State University

Tricorn Triangles

For Teachers K - 1st Standards
Help your learners examine triangles. Pupils explore the different sizes and measurements of triangles. They discover triangles can be isosceles or scalene, and examine the attributes of triangles. Here is the website where you can...
Lesson Plan
Curated OER

Does Your Field Measure Up

For Teachers 9th - 11th
Learners measure angles using a plane table kit. In this geometry lesson, students use trigonometric identities to find the values of the length of a football field.
Instructional Video14:57
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Flipped Math

Similar Figures

For Students 9th - 12th Standards
Use some similar problems to find side lengths. Pupils learn the definition of similar figures and how it relates to corresponding angles and sides. Using the definition, individuals calculate the lengths of missing sides and practice...
Lesson Plan
Curated OER

Exploring Geometric Figures

For Teachers 10th
Tenth graders explore mathematics by participating in hands-on daily activities. Learners identify a list of different shapes and classify them by shape, size, sides and vertices. They utilize tangrams and geometric pieces to gain...
Lesson Plan
EngageNY

Informal Proof of the Pythagorean Theorem

For Students 8th Standards
Prove the Pythagorean Theorem using multiple informal proofs. Scholars first develop an understanding of the origins of the Pythagorean Theorem through proofs. They round out the lesson plan by using the theorem to find missing side...
Lesson Plan
Curated OER

Inscribed Right Triangles

For Teachers 7th - 9th
Learners calculate the measurements of the inscribed angles of a triangle. For this geometry lesson, students relate the hypotenuse of a right triangle and the diameter of a circle to each other. They calculate the diameter of a circle...
Lesson Plan
Curated OER

Pythagorean Theorem and Problem Solving

For Teachers 9th - 10th
Learners use the Pythagorean Theorem to solve problems. In this geometry lesson, students identify the properties of a right triangle. They find the missing side and angles of a right triangle.
Worksheet
Curated OER

Trigonometric Ratios

For Students 10th
In this trigonometric ratios worksheet, 10th graders solve 9 different problems that include determining the trigonometric ratios of each triangle. First, they determine the sides and angles of a right triangle that is shown in each...
Lesson Plan
Curated OER

Angle Exploration and Classification

For Teachers 4th - 7th
Students compare and contrast angles and identify them as acute, obtuse, right, or straight angles. They create rays and angles using uncooked spaghetti, read and discuss key vocabulary terms, and complete a variety of geometry worksheets.
Worksheet
Curated OER

Triangles

For Students 10th
In this triangles worksheet, 10th graders solve and complete 22 different problems related to various types of triangles. First, they name the shortest and longest sides and the smallest and largest angles in each of triangles...
Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles learning exercise, 10th graders solve and complete 14 various types of problems. First, they find the perimeter of the isosceles trapezoid shown. Then, students find the measures of each marked side of a right...
Worksheet
Curated OER

Right Triangles

For Students 10th
In this right triangles learning exercise, 10th graders solve 10 different problems that include various right triangles. First, they find the value of a base given its hypotenuse. Then, students determine an angle given the perimeter...
Worksheet
Curated OER

Shapes and Designs

For Students 10th
In this shapes and designs worksheet, 10th graders solve and complete 6 different types of problems. First, they fill in the first two columns of the table show with their shapes. Then, students measure the interior angles of each...
Lesson Plan
Curated OER

Congruent Triangles

For Teachers 9th - 12th
High schoolers explore the concept of congruent triangles.  In this congruent triangles instructional activity, students use Cabri Jr. to construct two congruent triangles using circles.  High schoolers determine if the two...
Worksheet
Curated OER

Geometric Shapes and Angles

For Students 10th
In this geometry activity, 10th graders review polygons and solve for the missing angles of trapezoids and isosceles triangles. There are 10 questions on this activity with an answer key.
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.
Lesson Plan
Curated OER

Investigation - Adrienne's Pattern Block Angles

For Teachers 5th
Fifth graders investigate possible solutions to a word problem. They explore properties of polygons and right angles. Students demonstrate proper angle measurement. Students discover patterns.
Worksheet
Curated OER

Proofs

For Students 8th - 11th
In this geometric proof activity, students compose 20 triangle congruency proofs. Students will decide if there is enough information in problems 1-6 to prove if any triangles are congruent. In problems 17 to 20, students use given...
Lesson Plan
Curated OER

Art or Junk? Discovering the Triangle Inequality

For Teachers 6th
Middle schoolers study the triangle inequality. They will identify, compare, and analyze attributes of two and three-dimensional shapes. Then they develop vocabulary to describe the attributes. They also use manipulatives to analyze the...
Worksheet
Curated OER

Lengths of Horizontal and Vertical Line Segments

For Students 5th - 7th
Use this lengths of horizontal and vertical line segments practice worksheet to have learners sharpen their problem solving skills as they solve six story problems.
Lesson Plan
Curated OER

Right Triangles

For Teachers 4th - 8th
Learners classify triangles and make connections regarding angle measurements and attributes of acute, right, and obtuse triangles. They listen to teacher define and explain triangles. Everyone imagines a place where a broken wing for a...