Here are game websites to practice anything Geometry - area, volume, Pythagorean Theorem, etc...

http://www.math-play.com/Pythagorean-Theorem-Game.html

http://www.kidsmathgamesonline.com/geometry.html

http://www.onlinemathlearning.com/math-games.html

http://www.ixl.com/math/grade-8