Åk 6–9
1.2 History
The Greek philosopher Plato, who lived 2,500 years ago ran a school, the “Platonic Academy” in Athens. Above the entrance stood: “No one ignorant in Geometry may enter under my roof.”

This says something about how important mathematics was considered and how highly geometry was valued during this time. Plato himself wasn’t even a mathematician!

Almost at the same time as Plato live Euclid.  He studied at Plato’s school and engaged himself so strongly in geometry that he wrote more than 20 book on the subject.  Thirteen of the books are included in the work, “Elementa”.  This book was used in teaching far into the 1800’s.

Long before Plato and Euclid lived, there was a large interest in geometry in Egypt and Babylon.  Angles where useful in order to better understand and solve problems in for example astronomy and construction.  They also knew about the relationships between sides of the right triangle which later became known as Pythagorean Theorem.  Pythagoras, himself born 1,500 years later, was the person who could prove that the theorem applies for every triangle in the world that has a right angle.

A normal compass is divided into 360 degrees.  By reading the number of degrees (or how big the angles are), you can orientate yourself in respect to the four cardinal directions.