The document discusses sectioning of solids and includes definitions of key terms like cutting plane, section, sectional view, true shape of section, and apparent shape of section. It then provides examples of cutting various solids like cubes, prisms, and pyramids with different orientations of the cutting plane and calculating the true shape of the section. A total of 12 problems are included with diagrams showing the front and top views as well as the true shape of the section for each solid.