Sensing distance and area
This is based on "Sensing Distance and Area" by MITscratcher. I used "Heron's Formula" to find the area of the triangle using the lengths of its sides. Challenge to my students - create versions for other-sided polygons!
Find out more on Heron's Formula at http://mathcentral.uregina.ca/QQ/database/QQ.09.01/bat1.html