Introducing
Your new presentation assistant.
Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.
Trending searches
Alternate angles: angles on opposite sides of a transversal line, which are equal in size
blue angle
green angle
The red angle is identical in both forms. Since a straight angle consits of two right angles (=180°) we can conclude that the sum of the green, blue and red angle is 180°.
source: Thales of Miletus, PDF
source: Thales of Miletus, PDF
Definition: If A, B, and C are distinct points on a circle where the line AC is a diameter, the angle <ABC is a right angle.
source: Wikipedia
Initial Situation: "Suppose S is the common starting point of two rays, and two parallel lines are intersecting those two rays. Let A, B be the intersections of the first ray with the two parallels, such that B is further away from S than A, and similarly C, D are the intersections of the second ray with the two parallels such that D is further away from S than C."
source: Wikipedia
source: Wikipedia; Thales of Miletus, PDF
The ratio of any two segments on the first ray equals the ratio of the according segments on the second ray.
The ratio of the two segments on the same ray starting at S equals the ratio of the segments on the parallels.
"Thales was known for introducing the theoretical and practical use of geometry to Greece, and has been described as the first person in the western world to apply deductive reasoning to geometry."
source: Wikipedia
Deduction = a form of pure reasoning
The thinker starts with certain first principles, and argues from them until he reaches, through the use of logic, some conclusion. [...] he uses only facts that are agreed first principles or have themselves been proved from such first priciples.
source: Alfred Hooper
source: Wikipedia
The ratio of any two segments on the first ray equals the ratio of the according segments on the second ray.
A circle is bisected by any diameter.
B
A
S C D
The base angles of an isosceles triangle are equal.
Said to be found in his travels to Egypt, which he visited during his days as a merchant.
He tried to find an explanation for the geometric facts that were discovered empirically by the Egyptians.
In Egypt he calculated the height of the pyramids by measuring the shadows. Which means, that he measured the size of the pyramid at the exact time, when his own shadow was as big as himself.
Hans-Joachim Fischer
Wikipedia
The angles between two intersecting straight lines are equal.
Wikipedia
04
Two triangles are congruent if they have two angles and the included side equal.
source: Alfred Hooper
Wikipedia
05
An angle in a semicircle is a right angle (Thales' Theorem).
source: Thales of Miletus, PDF
Thales' geometry was committed to solve practical problems, e.g., to determine the distance from a ship at sea to land.
Dr. Klaus Mainzer
source: Hans-Joachim Fischer
source: Wikipedia
source: Lambacher Schweizer
source: A. A. Long
source: Wikipedia
The aim of the Milesian School was to explain nature by finding its fundamental element (=arche).
source: Wikipedia
source: Wikipedia
source: Wikipedia; Thales of Miletus, PDF
!
None of Thales's writing survived and no contemporary sources exist; thus, his achievements are difficult to assess, particularly his philosophy and mathematical discoveries.
One must consider the ancient practice of crediting particular discoveries to men with a reputation for wisdom.
548/545 B.C.
today
624 B.C.
source: Thales of Miletus, PDF
624 B.C. - 548/545 B.C.
source: Alfred Hooper, Wikipedia
When Thales got asked what he found difficult, he answered "knowing yourself". Adding to that, he answered the question, what he finds very easy, with "to give advice".
Wikipedia
In general, he believed that the earth is a flat disk, which floats on an endless expanse of water. He explained his theory by seeing water as the arche, which means that he believed that everything is born out of water.
He explained earthquakes through this theory, by saying that they occur when the earth is rocked by waves.
Thales investigated the world on a non-religious basis and tried to find naturalistic explanations of the world.
Astronomy
The ancient myths of Greek culture and society, build a theoretical foundation for the Milesian School.
The (origin of the) world was explained through mythology.
source: Wikipedia
Game-Pin: 151 1631
https://create.kahoot.it/creator/fdbe9c51-159f-48d4-bd84-fc4d526313bb
source: OLD, Keimpe Algra
Wikipedia
1. "Thales was studying the stars and gazing into the sky, when he fell into a well, and a servant girl made fun of him."
An actual story reported by Plato, Diogenes Laertius, and Hippolytus.
2. Thales predicted a solar eclipse.
It is said, that he predicted an eclipse that took place on May 28th, 585 B.C.
3. Thales demonstrated the use of natural philosophy by predicting the weather and renting olive presses to gain money.
By that he proved the usefulness of philosophy to the Milesians.
4. A crater on the moon is named "Thales" to honor him.
The crater Thales is located in the northeast part of the moon.
5. He died while watching the Olympic Games.
Reported by Diogenes Laertius.
Wikipedia
main source: Wikipedia