First, the world is built of shape and space, and geometry is its mathematics. Second, informal geometry is good preparation. Students have trouble with abstraction if they lack sufficient experience with more concrete materials and activities. Third, geometry has more applications than just within the field itself. Often students can solve problems from other fields more easily when they represent the problems geometrically.
Geometry can be a doorway to their success in mathematics.
Informal geometry has an equity component as well. They know that if the legs are blue, the hypotenuse is red. When they study geometry or learn the Pythagorean theorem, they already have the background textbook writers and teachers may unconsciously take for granted. So teachers, be watchful. The activities in this lab will help you bring this practice to your teaching.