RS Aggarwal Solutions for Class 8 Chapter 19 "Three-dimensional-shapes" this page examines the properties of three-dimensional or 'solid' shapes. A two-dimensional shape has length and width. A three-dimensional solid shape also has depth. Three-dimensional shapes by their nature, have inside and outside, separated by a surface. Geometry can be divided into two types: plane and solid geometry. Solid geometry involves objects of three-dimensional shapes such as cylinders, cubes, spheres, etc. Three-Dimensional Figures deals with the definition of solids, faces, vertices and edges of a Three-Dimensional Figures such as cuboid, cube, etc., and also deals with Euler's relation for Three-Dimensional Figures.