Connections: Comparing Regular and Irregular Areas

Everyday Math (2004)
Unit 8: Perimeter and Area, Grade 4
pp. 113-114 in Student Reference Book
pp. 607-621 and 641-642 in Teacher Guide

Investigations/Scott Foresman(2006)
In Flips, Turns and Areas Grade 3
Investigation 1: Motions and Tetrominoes
Investigation 2: Finding Area