The Geometry of Compasses; or, Problems Resolved by the mere Description of Circles, and "the Use of Coloured Diagrams and Symbols". By Oliver Byrne. (London: Crosby Lockwood and Co., 1877.) ...
Dividers and compasses are drawing instruments that have been used since antiquity to measure distances, transfer lengths from one drawing to another, and draw circles. The Greek mathematician, Euclid ...
place your compass at the other end of the line and draw another arc - crossing the first arc in two places. Follow the instructions and draw the perpendicular from a point to a line construction.