eBook
Mathigon

Mathigon: Geometry: Triangles and Trigonometry: Pythagoras' Theorem

For Students 9th - 10th Standards
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)
Handout
University of St. Andrews (UK)

University of St. Andrews: Pythagoras of Samos

For Students 9th - 10th
Provides much information on the life of Pythagoras of Samos.
Handout
Cut the Knot

Cut the Knot!: Analogues and Generalization of the Pythagorean Theorem

For Students 9th - 10th
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.
Activity
Cut the Knot

Cut the Knot!: The Law of Cosines (Cosine Rule)

For Students 9th - 10th Standards
This site from Cut The Knot provides an overview of the law of cosines, complete with an explanation of the law and a proof of the law.
Handout
World History Encyclopedia

World History Encyclopedia: Greek Mathematics

For Students 9th - 10th
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...

Other popular searches