Playing with Constructions

About this chapter

Playing with Constructions is Chapter 8 of Class 6 Ganita Prakash. It builds the basic tool kit of plane geometry — a ruler and a compass — and shows how every figure on the page begins as a planned set of points, lines and arcs. The chapter develops six core ideas: a curve is any shape drawn with a pencil and a circle is the special curve of all points at a fixed distance from a centre; a compass draws circles and arcs because it keeps the centre fixed and the radius constant; squares and rectangles are defined by side and angle properties (R1, R2 for rectangle; S1, S2 for square); a square can be constructed using either a protractor and ruler or a compass to copy the side; a rectangle can be constructed when both sides are given, or when one side and a diagonal are given, by using a perpendicular and an arc to locate the missing corner; and a figure like the House is built by chaining circles and arcs to find points equidistant from two given points. CTET Paper 2 Mathematics tests this chapter through identifying tools, ordering construction steps, spotting wrong-radius or wrong-centre errors and judging which property a step uses. The four tests below cover these ideas at the right depth.