A novel way to find areas using tangents. Harry http://www.its.caltech.edu/~mamikon/VisualCalc.html
"Calculus is a beautiful subject with a host of dazzling applications. As a teacher of calculus for more than fifty years and as an author of a couple of textbooks on the subject, I was stunned to learn that many classical problems in calculus can be easily solved by an innovative visual approach that makes no use of formulas." "The method was conceived in 1959 by a young undergraduate student at Yerevan University in Armenia named Mamikon A. Mnatsakanian."
