Students find the length of the hypotenuse using the Pythagorean Theorem. In this geometry lesson, students solve for the different parts of a right triangle. They work the first problem with-the teacher then work on their own.

In this triangle inequality instructional activity, students test the Triangle Inequality Theorem. They measure the sides of given triangles, identify the type of triangle, and name angles in the triangle. The one-page instructional...

Fourth and fifth graders study the Pythagorean Theorem and apply it to find the missing side of a right triangle.

In this Pythagoras' Theorem activity, students read through an explanation of how to solve problems with Pythagoras' Theorem and answer 4 questions in the explanation. Then, students use Pythagoras' Theorem to answer 6 problems. They can...

A lengthy narrative about Pythagoras and his students precedes an activity in which your young mathematicians practice using the Pythagorean theorem to solve three problems about flight and distance. Answers are provided. 

Looking at numerous examples of triangles, each with different properties, geometers develop their understanding of congruency. They use the notation of a counter-example to disprove certain conjectures and prove geometric theorems and...

Is this enough to show the two triangles are congruent? Small groups work through different combinations of constructing triangles from congruent parts to determine which combinations create only congruent triangles. Participants use the...

It is all about where the side is located. Pupils use their knowledge of angles in standard position to find reference angles. They use the Pythagorean Theorem to find lengths along a terminal side of an angle to determine the exact...

In this geometry worksheet, students identify the different ratios of triangles using the theorems. They use SSS, SAS, ASA and AAS to differentiate between triangles. There are 7 questions with an answer key.

Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...

Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...

Learners research Pythagoras and learn how to apply his theorem. They solve real life problems using the theorem and demonstrate knowledge of exponents, equations, and radicals. Students include diagrams in their research papers.

This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...

Everyone knows that opposite sides of a parallelogram are congruent, but can you prove it? Challenge pupils to use triangle congruence to prove properties of quadrilaterals. Learners complete formal two-column proofs before moving on to...

In this triangle similarity instructional activity, 10th graders solve and complete 12 different problems that include defining similar and 3 similar statements using only sides and angles. First, they determine if each pair of triangles...

Students investigate the relationship of triangles with its sides and angles. In this geometry lesson, students create visual on the graphing navigator as they study triangles. They move the sides around to create different angle-side...

Students investigate the relationship between angles and their sides. In this geometry lesson, students prove why SSA does not work as a true angle side relationship theorem.

Students identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.

Students investigate the side splitter theorem. In this geometry lesson, students estimate and solve problems dealing with ratios and proportions. They identify angles created by lines that are parallel.

In this geometry worksheet, students differentiate between isosceles and regular triangles. They calculate the area and perimeter of the triangle. There are eleven questions with an answer key.

Students use the inequality theorem to solve triangles and their properties. In this geometry lesson, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...

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...

In this congruent triangles worksheet, students solve four multiple choice problems. Students determine which statement is the appropriate reasoning to say that two triangles are congruent.

The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...