(a) Find the number of lines of symmetry of the following figure?
(b) How many angles of rotation will a regular polygon have if it has ‘n’ sides?
[4 MARKS]
(a) Answer : 1 Mark
Reason: 1 Mark
(b) Solution: 2 Marks
(a) The answer is 0.
When the line joining the midpoints of opposite sides divides the figure into two equal halves, such lines are called lines of symmetry. But the lines should not pass through the alphabets. Here no lines of symmetry are possible as no such line can be constructed which would divide the table without cutting through the alphabets.
(b) Angles of rotation of a regular polygon with ‘n’ sides = Y = n – 1
This is because the last rotation, i.e. 360∘ is not counted as an angle of rotation. If it was counted as an angle of rotation, every object would have an angle of rotation.
So, angles of rotation for a square are 90∘, 180∘ and 270∘. It’s only 3, not 4.