Khan Academy
Khan Academy: Pythagorean Theorem Challenge
In this exercise, students practice using the Pythagorean Theorem in word problems. Students receive immediate feedback and have the opportunity to watch a video, get hints, or try questions repeatedly.
Math Planet
Math Planet: Pre Algebra: The Pythagorean Theorem
Learn all about the Pythagorean Theorem by viewing examples and a video lesson.
Illustrative Mathematics
Illustrative Mathematics: 8.g Converse of the Pythagorean Theorem
This task asks students to explain what the Pythagorean Theorem and its converse are, how the converse works, and why it is true. Aligns with 8.G.B.6.
Varsity Tutors
Varsity Tutors: Hotmath: The Pythagorean Theorem
Twenty problems cover various aspects of the Pythagorean Theorem. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution" button to check each...
Doina Popovici
Math Play: Pythagorean Theorem Jeopardy Game
This jeopardy-style game will have students calculate the sides of a right triangle by using the Pythagorean Theorem.
Illustrative Mathematics
Illustrative Mathematics: F Tf Trigonometric Ratios and the Pythagorean Theorem
The purpose of this task is to use the Pythagorean Theorem to establish a fundamental trigonometric identity for an acute angle. The reasoning behind this identity is then applied to calculate a cosine for a given obtuse angle. Aligns...
Cut the Knot
Cut the Knot!: Analogues and Generalization of the Pythagorean Theorem
This site discusses the theorems and other findings which are directly related to the fundamental Pythagorean theorem. Be sure to click on the link to information on Pythagorean theorem to find several proofs of the theorem.
Purple Math
Purplemath: The Pythagorean Theorem
Defines the Pythagorean Theorem, and demonstrates how to use this Theorem in connection with right-angled triangles.
Illustrative Mathematics
Illustrative Mathematics: 8.g Pythagorean Theorem in Mathematical Context
Eighth graders are shown a drawing of a rectangle with a central triangle bordered by three right triangles. They are asked to prove whether or not the middle triangle is also a right triangle. Aligns with 8.G.B.
Shodor Education Foundation
Shodor Interactivate: Interactive: Pythagorean Explorer
Students find the length of a side of a right triangle by using the Pythagorean Theorem and then check their answers.
Shodor Education Foundation
Shodor Interactivate: Pythagorean Explorer
Calculate the length of one side of an automatically generated right triangle by using the Pythagorean Theorem, and then check your answers.
Mathigon
Mathigon: Geometry: Triangles and Trigonometry: Pythagoras' Theorem
Pythagoras' Theorem: In any right-angled triangle, the square of the length of the hypotenuse (the side that lies opposite the right angle) is equal to the sum of the squares of the other two sides. (A+B=C)
Shodor Education Foundation
Shodor Interactivate: Squaring the Triangle
Students explore the relationship between the Pythagorean Theorem and right triangles. Teacher resources are included.
Illustrative Mathematics
Illustrative Mathematics: G Gpe Squares on a Coordinate Grid
The purpose of this task is to use the Pythagorean Theorem and knowledge about quadrilaterals in order to construct squares of different sizes on a coordinate grid. Aligns with G-GPE.B.7.
Illustrative Mathematics
Illustrative Mathematics: G Gpe Triangle Perimeters
Students are shown two triangles touching points on a coordinate grid and are asked to answer questions about their perimeters. The purpose of this task is to apply the Pythagorean theorem to calculate distances and areas. Aligns with...
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 1
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.
Illustrative Mathematics
Illustrative Mathematics: F Tf Special Triangles 2
Using known facts about the unit circle and isosceles triangles together with the Pythagorean Theorem, students can derive the sine and cosine of special angles. Aligns with HSF-TF.A.3.
Illustrative Mathematics
Illustrative Mathematics: 8.g a Rectangle in the Coordinate Plane
In this task, 8th graders are shown a picture of a quadrilateral on a coordinate grid and are asked to use the Pythagorean Theorem to find lengths and to explain why the quadrilateral is a rectangle. Aligns with 8.G.B.
Illustrative Mathematics
Illustrative Mathematics: 8.g Area of a Trapezoid
Eighth graders are given various dimensions of a trapezoid and are asked to find its area. This requires them to use the Pythagorean Theorem and to decompose the trapezoid into other polygons. Aligns with 8.G.B.7.
Illustrative Mathematics
Illustrative Mathematics: 8.g Two Triangles' Area
In this task, 8th graders are given the dimensions of two isosceles triangles and are asked to compare their areas. They must draw them and use the Pythagorean Theorem and the triangle area formula to solve the problem. Aligns with 8.G.B.7.
Shodor Education Foundation
Shodor Interactivate: Squaring the Triangle
Learn about how the Pythagorean Theorem works through investigating the standard geometric proof.
World History Encyclopedia
World History Encyclopedia: Greek Mathematics
Discusses the major cultural influences on the development of mathematics in ancient Greece, and how the Greeks went on to surpass those cultures. The work of the Pythagoreans and of Euclid are described, along with some famous...
CK-12 Foundation
Ck 12: Trigonometry: Lengths of Sides in Isosceles Right Triangles
[Free Registration/Login may be required to access all resource tools.] Here you'll learn what an isosceles right triangle is, the relationships between the sides of an isosceles right triangle, and how to find the length of an unknown...
Khan Academy
Khan Academy: Distance Formula
Review how to derive a general formula for the distance between two points.