Best Known As: the Scientist They Named the Pythagorean Theorem After

Part III – Pythagoras & Pythagoras’ Theorem

§ Born: c. 580 B.C.

§ Birthplace: Samos, Greece

§ Died: c. 500 B.C.

§ Best known as: The scientist they named the Pythagorean Theorem after

Pythagoras lived in the 500's B.C., and was a Greek philosopher and mathematician. He also made important developments in astronomy and the theory of music. In the modern world Pythagoras is most of all famous as a mathematician, because of the theorem named after him. The theorem is likely to have been known to the Babylonians 1000 years before the time of Pythagoras, but he was the first to prove it.

Pythagoras' theorem states:

In any right-angled triangle, the area of the square whose side is the hypotenuse (the side opposite the right angle) is equal to the sum of the areas of the squares whose sides are the two legs (the two sides that meet at a right angle).

The theorem can be written as an equation: a2 + b2 = c2

where c represents the length of the hypotenuse, and a and b represent the lengths of the other two sides.

The square on the hypotenuse is equal to the sum of the squares on the other two sides.

British English / American English
Pythagoras' theorem / Pythagorean theorem
right-angled triangle / right triangle

I. Mark the sentences true (T) or false (F). Correct the false ones.

1. Pythagoras lived in the late 6th century A.D.. / T / F
2. Pythagoras was one of the first and most famous early Greek thinkers. / T / F
3. It is believed that Babylonian mathematicians proved the theory of Pythagoras’ theorem
before him. / T / F

4. A hypotenuse is the longest side of a right-angled triangle, the side opposite the right

angle.

/ T / F
5. The theorem is of fundamental importance in geometry where it serves as a basis for the
definition of distance between two points. / T / F

II. Pythagoras’ Theorem

STORY - Having trouble remembering Pythagoras’ Theorem? This short cartoon could help.

http://www.curriculumbits.com/prodimages/details/maths/mat0001.html

DEMO I - A short animated demonstration of Pythagoras’ Theorem with commentary.

http://www.curriculumbits.com/prodimages/details/maths/mat0002.html

DEMO II (Slovene) - http://ro.zrsss.si/projekti/pitagora/sld001.htm

III. HOMEWORK

Do the interactive exercise on the class blog.

http://www2.arnes.si/~sspmsubi/maths1.htm