A Quick and Simple Dictionary

pentagraph

Noun.  A device used in surveying composed of four flat, straight brass rules, two of which are long and are connected by a double pivot at the end to create a "V" shape, and two of which are short and joined by a double pivot to create another "V" shape pointed away from the first, with the other ends of the short rules connected at the halfway mark of the long rules, so that the entire figure creates a parallelogram.