1. Important Mathematicians Then and Now

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

3. Lived about 624 BC to 546 BC in Miletus, Asia Minor (now Turkey)
THALES
2,000BC ,000BC ,000AD ,000AD
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.

4. Contemporaries
Pythagoras

5. 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.

6. 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.

7. 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.

8. Quotes Answers Given by Thales
What is very difficult?
Thales answered, in a famous 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!!)

9. Anecdote Credit: http://phoenicia.org/thales.html
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:

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

11. Reflections about Thales:
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.

12. Clipart Credit: google.com
Annotated References
Thales of Miletus ,
Highlights of the life of Thales.
Thales Of Miletus 600 B.C.
A Student’s biography of Thales.
Encyclopedia Phoeniciiana Thales of Miletus
Conflicting stories about Thales.
Discovering Geometry Second Ed., Serra, M., Key Curriculum Press, 1997, page 718
Our Textbook
Clipart Credit: google.com

13. The End