Each part: 1 Mark
(a) If a fan has rotational symmetry of order 4, this means that the fan looks exactly as it was before the rotation at four instances. This can only happen when it has four blades.
(b) Square has both line and rotational symmetry of order more than 1.

The line of symmetry is a line which divides the given diagram into two equal mirror images. So, here the number of lines are 3.

(a) Answer: 1 Mark
     Diagram: 1 Mark
(b) Answer: 1 Mark
(a) For every 90 degrees of rotation, the figure looks the same.

Therefore the figure has an order of rotational symmetry of 4.
(b) A parallelogram has no line of symmetry.

Number of lines = 0

Figures: 1 Mark each
(i) 1 line of symmetry
 
(ii) 1 line of symmetry​​​​​​​

 (iii) 1 line of symmetry
 

No. of lines of symmetry: 1 Marks
Diagram: 2 Marks
Any line which divides a diagram into two equal halves is called a line of symmetry. This line of symmetry divides the figure into two identical halves. If a random diagram has 7 such lines, it will have 7 lines of symmetry.
The most basic figure that would have 7 lines of symmetry would be a regular heptagon with all 7 sides equal. Such a figure will have 7 lines of symmetry.

Each part: 1 Mark
(a) In order to identify the total number of lines of symmetry, we first have to identify the line through which we can fold the figure in such a way that two parts can overlap each other. Hence we find that this figure has five lines of symmetry.

(b) A regular pentagon has 5 lines of symmetry.

(i) Correct answer: 1 Mark
(ii) Correct answer: 2 Marks
(i) Z, H, N have rotational symmetry.
    If the given alphabets are rotated about a line passing through their centres, it resembles the same alphabet.
(ii)
(a) 

Completed Figures: 1 Mark each
(i)

(ii)
  
(iii)
     
(iv)