Lesson Plan
Curated OER

Special Right Triangles

For Teachers 9th - 10th
Students identify different types of special right triangles. In this geometry lesson, students differentiate between right triangles and isosceles triangles. they construct the triangles using geometry software and make conjectures...
Lesson Plan
Curated OER

Exploring the Hinge Theorem

For Teachers 9th - 10th
Students explore the application of Hinge Theorem. For this geometry lesson, students write inequalities, given two sides of a triangle. They solve problems with triangular inequalities using the proper theorem.
Lesson Plan
Curated OER

The Sierpinski Triangle

For Teachers 9th - 10th
Learners investigate the Sierpinski triangle. In this geometry lesson plan, students define fractal curves and its relationship to triangles. They identify repeating sequences and relate it to fractals.
Lesson Plan
Curated OER

Median

For Teachers 9th - 11th
Students solve problems involving triangles. In this geometry lesson, students use the properties of triangles to find the angles and side. They identify the median and altitude of the triangle.
Lesson Plan
Curated OER

Hospital Locator

For Teachers 7th - 9th
Learners apply properties of triangles to the real world. In this geometry lesson plan, students identify the median and angle bisectors of triangles. They plan the appropriate are to place a new medical center based on their knowledge...
Lesson Plan
Curated OER

Lines In Geometry

For Teachers 8th - 10th
Learners define important vocabulary words using a dictionary. For this geometry lesson, students identify and use properties of triangles to solve problems. They identify the median. altitude and angles as well as properties of...
Worksheet
Curated OER

Finding the Angle Measurements in Isosceles Triangles

For Students 9th
In this angles activity, 9th graders find the angle measurements in four isosceles triangles.  Two of these triangles are drawn inside a circle, where two of the sides of the triangles are formed by radii.
Lesson Plan
Curated OER

Identifying Triangles

For Teachers 6th
Sixth graders identify and define a variety of triangles. In this identification of triangles lesson, 6th graders draw examples of each triangle on a whiteboard, then complete a worksheet.
Worksheet
Curated OER

Area and Perimeter

For Students 10th
In this geometry activity, 10th graders use single variable equations to solve problems focusing on area and perimeter of triangles, trapezoids, parallelograms, rectangles, and hexagons.  The one page activity contains seventeen...
Worksheet
Curated OER

Triangles

For Students 6th - 10th
In this triangles worksheet, students solve for the missing angles and missing sides on the triangles given. Students complete 12 problems total.
Worksheet
Curated OER

Area and Periemeter

For Students 10th
In this geometry worksheet, 10th graders determine the area and perimeters of various quadrilaterals and triangles.  The one page worksheet contains ten problems.  Answers are not provided. 
Lesson Plan
Curated OER

Angles and Triangles

For Teachers 8th
Eighth graders examine Jewish symbols. For this Holocaust lesson, 8th graders discuss the meanings behind the Swastika and the Star of David. Students also measure the angles and shapes with the symbols.
Worksheet
National Council of Teachers of Mathematics

How Many Triangles?

For Students 5th - 8th
For this triangles worksheet, learners problem solve and shade triangles within other triangles. Students complete two problems.
Worksheet
Curated OER

Find the Missing Side of the Right Triangle

For Students 6th - 8th
In this find the missing side of the right triangle worksheet, middle schoolers use the Pythagorean theorem to find the missing side, given the other 2 lengths, for 4 triangles.
Lesson Plan
Curated OER

Pascal's Patterned Triangle

For Teachers 5th
Fifth graders receive a brief history of Pascal's triangle. As a class the students construct the first few rows of the triangle. The students are then split into groups where they finish a worksheet identifying the total value of each...
Worksheet
Curated OER

Pythagorean Theorem for Algebra I

For Students 8th - 9th
In this Pythagorean theorem for algebra I worksheet, students answer 10 problems finding the missing side of a right triangle using the Pythagorean theorem.
Worksheet
Curated OER

Using Algebraic Equations in Geometry Problems

For Students 6th
For this using algebraic equations in geometry problems worksheet, 6th graders write an equation to solve each addition problem about geometry, then find the solution.
Worksheet
Print and Practice

Triangles and Rectangles

For Students K - 2nd
In this triangle and rectangle activity, students color triangles red and rectangles blue in a given set of shapes. A reference web site is given for additional activities.
Worksheet
Curated OER

Pythagorean Theorem

For Students 7th - 10th
In this Pythagorean theorem worksheet, students use the Pythagorean theorem to find the missing side of the triangle. Students complete 10 problems.
Worksheet
Curated OER

Cosine

For Students 10th - 12th
In this cosine instructional activity, students find the cosine of x for different measurements of triangles. Students complete 10 cosine problems.
Lesson Plan
Curated OER

Sine

For Teachers 10th - 12th
In this sine worksheet, students use the trigonometry equation to find the sine of triangles. Students solve the sine for 10 triangle problems.
Worksheet
Curated OER

Triangle Puzzle

For Students 2nd - 3rd
In this geometric shapes worksheet, learners analyze an intricate design of lines. Students look for all the triangles and tell how many there are.
Lesson Plan
Curated OER

Physics Lab Rockets

For Teachers 10th - 12th
Students construct and test balloon rockets and a model rocket. In this rocket science instructional activity, students use an inquiry-based method to master balloon rockets and have a shoot-off with the goal of attaining the highest...
Worksheet
Curated OER

Identify Triangles 2

For Students 2nd - 5th
In thins triangles review worksheet, students examine 4 triangles and their measurements. Students classify them as equilateral, isosceles, or scalene.