Symmetry NCERT Exercise 14.2
Question 1: Which of the following figures have rotational symmetry of order more than 1:
Answer: a, b, d, e, f
Question 2: Give the order of rotational symmetry for each figure:
Answer: (a) 2, (b) 2, (c) 3, (d) 4, (e) 4, (f) 5, (g) 6, (h) 3
Exercise 14.3
Question 1: Name any two figures that have both line symmetry and rotational symmetry.
Answer: Square, circle
Question 2: Draw, wherever possible, a rough sketch of
- A triangle with both line and rotational symmetries of order of more than 1.
- A triangle with only line symmetry and no rotational symmetry of order more than 1.
- A quadrilateral with rotational symmetry of order more than 1 but not a line of symmetry.
- A quadrilateral with line symmetry but not a rotational symmetry of order more than 1.
Answer: (a) Equilateral Triangle, (b) Isosceles Triangle, (c) Parallelogram, (d) Kite
Question 3: If a figure has two or more lines of symmetry, should it have rotational symmetry of order more than?
Answer: Yes
Question 4: Fill in the blanks:
Answer:
Shape | Centre of rotation | Order of rotation | Angle of rotation |
---|---|---|---|
Square | Intersection point of diagonals | 4 | 90° |
Rectangle | Intersection point of diagonals | 2 | 180° |
Rhombus | Intersection point of diagonals | 2 | 180° |
Equilateral triangle | Intersection point of medians | 3 | 120° |
Regular hexagon | Intersection point of diagonals | 6 | 60° |
Circle | Centre | Infinite | Any angle |
Semicircle | Centre | 1 | 360° |