NCERT Solutions for Ganita Prakash Chapter 9 Symmetry
Updated on 2026-09-05
About this chapter
A figure has symmetry when a part of it is repeated in a definite pattern. The flower, the butterfly, the rangoli and the pinwheel are symmetrical; a cloud is not. A line that cuts a figure into two parts that exactly overlap when folded along it is a line of symmetry (axis of symmetry). Such a figure is also said to have reflection symmetry . A figure may have many lines of symmetry — a square has 4, a regular hexagon has 6, a circle has infinitely many. If a figure looks exactly the same after being turned through an angle about a fixed point, that angle is an angle of symmetry and the fixed point is the centre of rotation . Since a 360° turn always brings a figure back, 360° is an angle of symmetry of every figure . The number of angles of symmetry is the order of rotational symmetry .
- & 218Chapter opening
- Line of Symmetry
- Paper Folding and Cutting
- Punching Game, Paper Cutting and Lines of Symmetry
- & 231Section 9.2 Rotational Symmetry
- Rotational Symmetry of Figures with Radial Arms
- & 236Section 9.2 Rotational Symmetry
- & 240Playing with Tiles
- The 6 by 6 grid game
Exercises
- & 218Chapter opening — In-text Questions Page 217
- Figure it Out — Line of Symmetry Page 219
- & 222Figures with more than one line of symmetry; Reflection — In-text Questions Page 221
- Paper Folding and Cutting — In-text Questions Page 223
- Punching Game, Paper Cutting and Lines of Symmetry — Figure it Out Page 223 to 230
- & 231Section 9.2 Rotational Symmetry — In-text Questions Page 230
- Rotational Symmetry of Figures with Radial Arms — In-text Questions Page 232 to 235
- & 236Section 9.2 Rotational Symmetry — Figure it Out Page 235
- & 237Multiples of the smallest angle; True or False; Symmetries of a circle — In-text Questions Page 236
- & 239Symmetries of a Circle; Regular Polygons; Ashoka Chakra — Figure it Out Page 238
- & 240Playing with Tiles — Playing with Tiles Page 239
- The 6 by 6 grid game — Game Page 241