Try these links to get you into area (the middle of a shape) and perimeter (the rim or edge of the shape)!
http://www.bgfl.org/bgfl/custom/resources_ftp/client_ftp/ks2/maths/perimeter_and_area/index.html
Can you do the Superbrain challenge on:
http://www.funbrain.com/poly/index.html
Can anyone come up with a better way of remembering what area and perimeter is than the rap below?