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The Pythagorean Theorem. By: Coach McCullers. One of the most influential theorems in Geometry!. Pythagoras: Brief History. Led a Italian society, half religious and half science, which was based on secrecy. Pythagoras believed: that at its deepest level, reality is mathematical in nature,
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ThePythagorean Theorem By: Coach McCullers One of the most influential theorems in Geometry!
Pythagoras: Brief History • Led a Italian society, half religious and half science, which was based on secrecy. Pythagoras believed: • that at its deepest level, reality is mathematical in nature, • that philosophy can be used for spiritual purification, • that the soul can rise to union with the divine, • that certain symbols have a mystical significance, and • that all brothers of the order should observe strict loyalty and secrecy. • Because of the secrecy, no writings or examples of his work exist. What we know about him comes from what others wrote about him.
Pythagoras: Brief History • He was interested in the principals of mathematics: • The concept of number • The concept of a triangle or other mathematical figures • The abstract idea of proof • The theorem, which bears his name, appears in other early mathematician’s writings.
What is the Pythagorean Theorem? • “The square of the hypotenuse of a right triangle is equal to the sum of the squares of the legs.” • In symbol notation, we write: a2 + b2 = c2
How to use it... • The longest side of the right triangle is called the hypotenuse (c). The hypotenuse is always located across from the right angle. • “a” and “b” represent the legs of the right triangle. • To use, substitute the known values in the Pythagorean Theorem and solve for the unknown.
Remember: legs a2 + b2 = c2 hypotenuse c a hypotenuse legs b
To Solve... • First write the Pythagorean Theorem. a2 + b2 = c2 hypotenuse c a legs b
Substitute known values... • Substitute in the values. 42 + 32 = c2 • Evaluate the squares. 16 + 9 = c2 • Add. 25 = c2 c 4 ft. 3 ft.
Solve for the missing variable. 25 = c2 • Take the square root of both sides. • Final Answer: c 4 ft. 3 ft.
A Flowchart to Follow... Write the Pythagorean Theorem Substitute in the values you know. Solve for the missing part of the triangle. Thank You, Mr. Pythagoras! CHECK YOUR ANSWER!
Your Turn! • Solve for the missing measurement. 13 ft. 5 ft. b
Answer 13 ft. 5 ft. b
Web References History Links: http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Pythagoras.html http://www.cut-the-knot.org/pythagoras/index.shtml http://history.hanover.edu/texts/presoc/pythagor.htm Links for Visual Proofs of the Pythagorean Theorem: http://www.dbai.tuwien.ac.at/proj/pf2html/proofs/pythagoras/pythagoras/pythagoras.html http://www.iusb.edu/~abrown/pyth-dem.html http://www.stats.uwaterloo.ca/%7Ecgsmall/pyth_anim.html http://www.tssi.com/Pythagoras%20Connections.html