30. Others

Given three parallel lines, show how to construct an equilateral triangle with one vertex on each line.

Steve's invariant problems: draw a figure which stays a parallelogram, and so on. (see extra pages)

Daina's angle trisectors in a triangle problem.

Airport problem: given three points ABC, find a point P such that the sum of the distances to the cities is a minimum. Try inductively, and then make conjectures about why this answer might work.

Mary Jean problems on geometric arithmetic.