RD Sharma Solutions for Class 7 Chapter 17 Constructions- It means to draw shapes, angles or lines using compass, ruler and pencil. "Construction" in Geometry means to draw shapes, angles or lines accurately. These constructions use the only compass, straightedge (i.e. ruler) and a pencil. It is the "pure" form of geometric construction: no numbers involved! Textbook deals with the topic of drawing a line parallel to the given line through a given point outside it, SAS triangle construction, SSS triangle construction, ASA triangle construction and RHS triangle construction.