- 1.4: Geometry
- Geometric shapes, as well as area and volumes, can often be important in problem solving.
- 1.7: Extension - Taxes
- Governments collect taxes to pay for the services they provide. In the United States, federal income taxes help fund the military, the environmental protection agency, and thousands of other programs. Property taxes help fund schools. Gasoline taxes help pay for road improvements. While very few people enjoy paying taxes, they are necessary to pay for the services we all depend upon.