| For those that can't find the angles of a pentagon: you can guess the pattern if you consider how many degrees are in a triangle and how many are in a quadrilateral (hint: it's an arithmetic sequence, not a geometric sequence). Also, there are ways, not extremely complicated, to calculate that limit, but it takes a couple years of college math, not high school.
Lastly, who has a life and remembers the trig double angle identities? It's easy enough to remember that sin^2 + cos^2 = 1, but sin(2x) has almost zero application for any math problem once you are out of precalculus. |
Polygons 
Types of Triangles 
Two-Minute Math (Differential Calculus)
