Middle and high schoolers construct a triangle using Cabri Jr. They construct squares on each of the legs and hypotenuse of the triangle. Pupils show that the area of the squares on the leg equal the area of the square on the hypotenuse.

The Pythagorean Theorem makes an appearance yet again in this lesson plan on polynomial identities. Learners prove a method for finding Pythagorean triples by applying the difference of squares identity. 

Learners construct a variety of right triangles using a right-angled set square, cutting corners from pieces of paper or cardboard, and using dynamic geometry software. They measure the sides of these various right triangles and record...

Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.

In order to learn about the Pythagorean Theorem, young mathematicians investigate relations and patterns between different sides of a right triangle to look for possible relations among the squared sides. Once they have established the...

There are many different ways to show a proof of the Pythagorean Theorem.  Here is a nice hands-on paper cutting activity that shows a graphic representation. You can even challenge your young Pythagoreans to come up with their own...

Young scholars identify different properties of parallelograms. In this geometry instructional activity, students complete problems that proves the theorems and properties of parallelograms. They graph the different shapes on paper.

Students solve problems using the pythagorean Theorem. In this geometry lesson, students complete proofs using the Pythagorean Theorem. They share their proofs and solutions with their classmates and family members.

Tenth graders connect the history of geometry to problem solving. In this geometry lesson, 10th graders investigate polygons through hands on manipulatives and solve problems relating to parallelograms and triangles. They calculate the...

Tenth graders investigate the theorems of angles and lines to prove triagle sum theorem. 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...

Students investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, students 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 two rays...

Students 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.