Ex.14.3 Q4 Symmetry - NCERT Maths Class 7
Question
Fill in the blanks – Shape; Centre of Rotation; Order of Rotation; Angle of Rotation; for each of the figures respectively.
|
Shape |
Centre of Rotation |
Order of Rotation |
Angle of Rotation |
| Square | |||
| Rectangle | |||
| Rhombus | |||
| Equilateral Triangle | |||
| Regular Hexagon | |||
| Circle | |||
| Semi-circle |
Text Solution
What is known?
Shapes
What is unknown?
Centre of rotation, order of rotation and angle of rotation.
Reasoning:
Centre of rotation: In case of polygon centre of rotation is intersecting point of diagonals and in case of circle centre of rotation is centre of the circle.
Order of rotation: In case of regular polygon order of rotation is always equals to the number of sides and in case of circle order of rotation is infinite.
Angle of rotation: In case of regular polygon angle of rotation is always equals to the measurement of one angle and in case of circle angle of rotation is at every point.
Steps:
|
Shape |
Centre of Rotation | Order of Rotation | Angle of Rotation |
| Square | Intersecting points of diagonals | \(4\) | \(90^\circ\) |
| Rectangle | Intersecting points of diagonals | \(2\) | \(180^\circ\) |
| Rhombus | Intersecting points of diagonals | \(2\) | \(180^\circ\) |
| Equilateral Triangle | Intersecting points of diagonals | \(3\) | \(120^\circ\) |
| Regular Hexagon | Intersecting points of diagonals | \(6\) | \(60^\circ\) |
| Circle | Mid- point of diameter | Infinite | At every point |
| Semi-circle | Mid- point of diameter | \(1\) | \(360^\circ\) |