Important Mathematicians Then and Now 1 T H

Important Mathematicians Then and Now 1

T H A L E S OF M I L E T U S Sample Presentation By Mrs. Brewster Clipart Credit: Thales. Encyclopedia Phoeniciiana 2

Lived about 624 BC to 546 BC in Miletus, Asia Minor (now Turkey) THALES 2, 000 BC 1, 000 BC 0 1, 000 AD 2, 000 AD The first known Greek philosopher, scientist and mathematician. The only Mathematician in The Seven Wise men of Antiquity. Introduced Geometry into Greece, after visiting Egypt. 3

Contemporaries Pythagoras 4

Accomplishments in Mathematics • Credited with five theorems of elementary geometry: Proposition. A circle is bisected by any diameter. Proposition. The base angles of an isosceles triangle are equal. Proposition. The angles between two intersecting straight lines are equal. Proposition. Two triangles are congruent if they have two angles and the included side equal. Proposition. An angle in a semicircle is a right angle. 5

More Accomplishments in Mathematics He calculated the size of the great pyramid, for the Egyptians, by using similar triangles. Pythagoras was his most famous student. 6

Other Accomplishments • He is said to have predicted an eclipse of the Sun on May 28, 585 BC, startling all of Ionia. • Thales is also said to have discovered a method of measuring the distance to a ship at sea. 7

Quotes Answers Given by Thales What is very Thales answered, in a famous difficult? witty saying, "To Know Thyself. " What is very easy? He answered, "To give advice. " What/who is God? He answered, "That which has no beginning or no end. " (The infinite!!) 8

Anecdote: Aristotle relates a story of how Thales used his skills to deduce that the next season's olive crop would be a very large one. He therefore bought all the olive presses and then was able to make a fortune when the bumper olive crop did indeed arrive. Anecdote Credit: http: //phoenicia. org/thales. html 9

Implications for Today Thales thought up many ideas which are used by people today, such as indirect measurement, and the idea of Infinity. 10

Conclusion. Reflections about Thales: Thales was a revolutionary thinker who impressed his contemporaries by being able to calculate the height of the Great Pyramid of Egypt. He is the first recorded person who tried to explain phenomena, like earthquakes, by rational rather than by supernatural means. Philosophy, Science and Mathematics were more important to Thales than family or wealth. 11

Annotated References Thales of Miletus http: //www. math. tamu. edu/~don. allen/history/thales 2. html , Highlights of the life of Thales Of Miletus 600 B. C. http: //www. mvrhs. org/netsite/school/departments/Math/Jen's%20 folder/thales_o f_miletus. htm A Student’s biography of Thales. Encyclopedia Phoeniciiana Thales of Miletus http: //phoenicia. org/thales. html Conflicting stories about Thales. Discovering Geometry Second Ed. , Serra, M. , Key Curriculum Press, 1997, page 718 Our Textbook Clipart Credit: google. com 12

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