Teacher presentation materials. Unit: Geo.5 Solid Geometry (Geometry). Geo.5 Solid Geometry In this unit, students practice spatial visualization in three dimensions, study the effect of dilation on area and volume, derive volume formulas using dissection arguments and Cavalieri's Principle, and apply volume formulas to solve problems involving surface area to volume ratios, density, cube roots, and square roots. Read More Lessons Resources Assessments Lessons Cross Sections, Scaling, and Area 1 Solids of Rotation 2 Slicing Solids 3 Creating Cross Sections by Dilating 4 Scaling and Area 5 Scaling and Unscaling Scaling Solids 6 Scaling Solids 7 The Root of the Pro