- der
- Peripheriewinkel
- : angle at the cirumference.
- [7]
- inhaltsgleich
- equal in area;
- der Inhalt
- : contents.
- [8]
- die Kathete
- : leg of a right-angled triangle.
- [9]
- Sei CAB ein ... Dreieck
- : let CAB be a triangle.
- [10]
- der ... Quadrate
- ; see
- 1 Note 10
- .
- [11]
- es lässt sich zeigen
- : it allowes itself to be shown = it may be shown. A common use of
- lassen
- .
- [12]
- Hülfslinien
- : auxiliary lines, construction lines.
- [13]
- see
- 1 Note 9
- .
- [14]
- d. i. (das ist)
- : that is to say (i. e.)
- [15]