Compass and Ruler

I take an adult education in the university named Shonan Institute of Technology. It’s quite a specific system of this university. It is not a special course for adults – anyone who pays a certain charge can take the same lecture for the very students! I go there every monday, to take three classes. I wish I could take more, but I have so many other things to do.

One of the classes I take is geometry. This class is for students going to be math teachers. So the content itself is at high-school level, which they learn for much more detailed explanations. I myself don’t plan to be a teacher. I just want to learn the things again.

Today I spent much time to do the homework of geometry.

The below is an exercise to set a midpoint on each side of a triangle. Perhaps you remember your school days. This task can be done only by a compass and a straight ruler. Draw circles of the same radius at both edges of a segment as their centers, and joint the two intersections, which will cross with the segment at its midpoint.

Using compass to set the midpoint of a segment

Join each vertex and the midpoint of the opposite side. The resulting three lines will cross at a single point…oh…a little deviation.

The three lines should cross at one point...

Today’s homework was heavy. I had to write so much in the answer sheet. I wish the teacher gave us a sheet with more space.

More space in the answer sheet, sir!
Anyway it’s fun to learn again.


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