Calçadas - I

Synopsis: the protagonists intend to make a garden in a triangular shape with a constant around the garden sidewalk width. To buy the proper materials they need to calculate the area of ​​the garden and the sidewalk. This is the problem they solve. (Part 1/2)
Source: Unicamp - M3, Mathematics and Multimedia.
URL: http://m3.ime.unicamp.br/recursos/1303