EngageNY
Criterion for Perpendicularity
The Pythagorean Theorem is a geometry pupil's best friend! Learners explain the equation a1b1 + a2b2 = 0 for perpendicular segments using the Pythagorean Theorem. They are able to identify perpendicular segments using their...
Charleston School District
Review Unit 8: Geometry Applicaitons
Pupils complete a review worksheet that highlights the key problems from the first eight lessons in the series. Topics include the Pythagorean Theorem and its converse, as well as finding volume of three-dimensional figures.
Curated OER
Distance Formula
Young scholars calculate the distance between two points using the distance formula. In this geometry lesson, students derive the distance formula using the Pythagorean Theorem.
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Curated OER
The Pythagorean Theorem
Seventh graders relate the Pythagorean theorem to the real world. In this algebra lesson, 7th graders identify important properties of the Pythagorean theorem and use it to solve word problems. They create a step by step plan to...
Curated OER
Logical Relationship of Postulates & Theorems
In this postulates and theorems activity, students explore a concept map containing information about angles and sides, alternate interior angles, and diagonals of a parallelogram. They use the concept map to prove theorems dealing...
Curated OER
Properties of Parallelograms
Learners identify different properties of parallelograms. In this geometry lesson, students complete problems that proves the theorems and properties of parallelograms. They graph the different shapes on paper.
Curated OER
Tangram Perimeters
Students work together to make figures out of tangram squares. In groups, they calculate the measurements they need and apply the Pythagorean Theorem. They complete a worksheet solving equations using the theorem and review their answers.
Maths Challenge
Maths challenge.net: Right Triangle Equal Parts
A geometry proof problem involving a right triangle and finding angles of equal measure.
Maths Challenge
Maths challenge.net: Right Angle Reasoning
A geometry problem for students to use their mathematical reasoning skills to explain a right triangle property.
CK-12 Foundation
Ck 12: Geometry: Inscribed Similar Triangles
[Free Registration/Login may be required to access all resource tools.] Apply the fact that the altitude of a right triangle creates similar triangles.
Texas Instruments
Texas Instruments: Proof of the Pythagorean Theorem Using Transformations
In this activity, students will explore visual proofs of the Pythagorean Theorem using area and transformations. They will use the Cabri Jr. app to perform translations on the squares constructed on the two legs and the hypotenuse of a...
Maths Challenge
Maths challenge.net: Leaning Ladders
Use your right triangle solving skills to solve this ladders in a hole problem.
Shodor Education Foundation
Shodor Interactivate: Squaring the Triangle
Learn about how the Pythagorean Theorem works through investigating the standard geometric proof.
National Council of Teachers of Mathematics
Nctm: Illuminations: Proof Without Words: Pythagorean Theorem
Students use this computer applet to visualize the Pythagorean Theorem.
Lawrence Hall of Science
The Math Page: Skill in Algebra: The Pythagorean Theorem
Here is a site that clearly and thoroughly explains the Pythagorean Theorem from solving for missing sides of a right triangle through its proof. There are example problems solved, problems for the student to attempt, and answers to the...
University of British Columbia
University of British Columbia: Proof of the Pythagorean Theorem
A geometric model that proves the Pythagorean Theorem in a step-by-step diagram that students can advance at their own pace. Requires Java.
Maths Challenge
Maths challenge.net: Corner Circle
This is a "three star" geometry problem where prior knowledge of circles and triangles is recommended to solve this circle in the corner problem.
Alabama Learning Exchange
Alex: The Pythagorean Theorem in the Real World
The introduction of this lesson plan has students verifying the famous Pythagorean Theorem with a hands-on proof. Students will then apply the Theorem in one of two ways: by solving for the side lengths of a right triangle and by...
CK-12 Foundation
Ck 12: Geometry: Pythagorean Theorem and Pythagorean Triples
[Free Registration/Login may be required to access all resource tools.] Apply the Pythagorean Theorem and its converse. Includes videos, exercises, links to interactive activities, etc.