vector rotation — live canvas animation example

motion & easing8+
trig, angles & vectors8-
collision detection11+
numbers in motion7+
geometry & shapes8+
generative showpieces13+
handy helpers7+

Every spoke is the same set of points run through vecRotate by a steadily growing angle. Rotation just remixes each point's x and y with sine & cosine — the orange dot marks where the shape 'starts'.