Interactive geometry to use now

Perimeter Point C divides the length AB in two. Drag point C back and forth along AB or click once on the "animate" button. The length and width of the rectangle remain equal to AC and CB and so the perimeter of the rectangle is constant. To change the value of the perimeter, drag on point B. (Adapted from Daniel Scher's Geometry in Motion site.) Press "r" to reset the sketch.