"Construction" in Geometry means to draw shapes, angles or lines accurately. These constructions use an only compass, straightedge (i.e. ruler) and a pencil. It is the "pure" form of geometric construction: no numbers involved! Students get to learn about 1. Division of a line segment in a given ratio (internally), 2. Tangent to a circle from a point outside it and 3. Construction of the triangle similar to a given triangle and so on.