Triangle Teacher Resources

It's frog party time! With frog banners, frog juice, and a triangle hunt, your garden party is sure to be both entertaining and educational. The lesson connects geometry, earth science, and delicious snacks to teach kids about ecosystems...

Need an activity for teaching the Pythagorean Theorem? Geometry juniors apply the Pythagorean theorem to two triangles to determine a final calculation. 

What can symmetry tell us about triangles? After looking at four examples, learners will come to realize that lines of symmetry are different for equilateral, isosceles, and scalene triangles. Use this guided practice activity as an...

While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...

Get lost in the classifications. Using the backdrop of the Bermuda Triangle, pupils classify it by angle and side measures. They also learn information about the triangle and its history.

Learners examine a figure made up of different types of triangles and then determine whether each triangle is right, acute, or obtuse. Next, they color each type of triangle a different color. Finally, pupils answer three fill in the...

An outstanding lesson plan on triangles awaits your math scholars. Learners focus on the triangle, which is the strongest of all polygons. They see the role that triangles play in the design of buildings, and learn about triangle...

In this math worksheet, students answer 3 questions about an equilateral triangle. Students then answer 3 questions about isosceles triangles. Students then calculate missing angles on isosceles triangles.

In this geometry worksheet, students answer 8 fill in the blank questions where they must examine 5 different complex geometric figures to classify triangles.

Given a pair of parallel lines and a triangle in between, geometers prove that the sum of the interior angles is 180 degrees. This quick quest can be used as a pop quiz or exit ticket for your geometry class.

This modern animation and discussion of the ancient secrets of Pascal's triangle manages to be topical, engaging, and mathematically deep all at the same time. A great introduction to the power of number theory across multiple math...

If you're looking for a presentation to assist you in your teaching of triangles, this one could be for you. In it, learners are shown how triangles are classified by the size of their angles and by their sides. These are tricky concepts...

Although a rather complicated topic, this video clearly explains the concept of solving problems involving similar triangles. It employs problem-solving to determine whether two figures are similar triangles. In addition, it provides...

Building on concepts in the first part of the series on similar triangles, installment number two explores how to find the values for given angles in a triangle. These problems are solved by using algebra and ratios. A step-by-step...

Creating a triangles is as easy as 5, 6, 7. Using a ruler and compass to measure off lengths, a short video shows how to construct a triangle with three specific side lengths. The example creates a triangle with side lengths of 5 cm, 6...

Don't believe everything that you hear — make them prove it! The video shows two methods to prove the Triangle Angle Sum Theorem. The following two videos apply the theorem to finding missing angle measures.

The narrator of a short video explains the steps in constructing a triangle given the measure of two angles and the length of the side between the angles. The resource provides opportunities for pupils to practice the skill with two...

This lecture explores finding the area of each of the triangles created by drawing two diagonal lines through a rectangle. It provides a detailed explanation of how to use a formula to solve the given problem. Tip: Use this for test...

This lecture explores the area of each triangle created by drawing two diagonal lines through a rectangle. It provides a detailed explanation of how to use a formula to solve the given problem. Tip: Use this for test preparation purposes.

Big Bird gives Telly a lesson on living vs. non-living things in this film. Telly is afraid to play a musical instrument, a triangle, he is holding because he thinks he might hurt it. After Big Bird tells Telly the triangle isn't living,...

After reviewing characteristics of seven types of triangles, young geometers discover how to find the missing angle of a triangle. Then, they practice identifying triangles, find missing angles, and find missing side lengths of...

Use the Pythagorean Theorem formula to check if this given triangle, with the given lengths of each side, is a right triangle. It's as simple as plugging the given values into the formula and doing the math to see if the solution checks...

Triangles, triangles, triangles. What makes a polygon a triangle? How many types of triangles are there? How do you determine what kind of triangle it is? Watch this video as the teacher explains 'tri' meaning three, making a triangle -...

Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....