ClassFlow
Class Flow: Goats and Monsters
[Free Registration/Login Required] Students explore methods to measure lengths of squares and radius of a circle in trying to keep a goat from escaping.
Shodor Education Foundation
Shodor Interactivate: Perimeter Explorer
Use this applet to find the perimeter of a variety of shapes with the same or different areas.
ClassFlow
Class Flow: Geoboards
[Free Registration/Login Required] Geoboards bring challenge into the classroom as the student uses methods to measure length, area, and perimeters of polygons.