Rice University
Rice University: Cynthia Lanius: Mathematics of Cartography: Projections
Understanding map projections is an important map-reading skill. Features graphics and links to examples of many different projections and an activity on making a Mercator projection.
Khan Academy
Khan Academy: Determine Rotations
Given a figure on the coordinate plane and a center of a rotation, find the angle for the rotation that maps one figure to the other.