Chapter 14 Symmetry
Very Short Answer Type
Question 1.
Draw any two English alphabets having an only a vertical line of symmetry.
Solution:
Question 2.
Draw any two English alphabets having a horizontal line of symmetry.
Solution:
Question 3.
Draw any two English alphabets having both horizontal and vertical line of symmetry.
Solution:
Question 4.
Dray any two English alphabets which has no line of symmetry.
Solution:
Question 5.
Draw any two figures which have the order of rotational symmetry 4.
Solution:
Question 6.
Draw any two figures which have the order of rotational symmetry 2.
Solution:
Question 7.
State the order of rotational symmetry of the following figures.
Solution:
(i) Order of equilateral triangle = 3
(ii) Order of regular pentagon = 5.
Question 8.
Draw a figure having an infinite number of lines of symmetry.
Solution:
A circle has the infinite number of lines of symmetry.
Question 9.
Draw any two figure having no lines of symmetry.
Solution:
English alphabet R and P have no lines of symmetry.
Question 10.
State the English alphabet which has only the horizontal line of symmetry.
Solution:
B, C, D, E, H, I, O, X and K are the English alphabets having an only horizontal line of symmetry.
Short Answer Type
Question 11.
Give the order of rotational symmetry of each of the following figures:
Solution:
(a) Order of rotational symmetry = 4
(b) Order of rotational symmetry = 5
(c) Order of rotational symmetry = 3
(d) Order of rotational symmetry = 6
(e) Order of rotational symmetry = 3
(f) Order of rotational symmetry = 4
Question 12.
How many lines of symmetry do the following have:
(a) a parallelogram
(b) an equilateral triangle
(c) a right angle with equal legs
(d) an angle with equal arms
(e) a semicircle
(f) a rhombus
(g) a square
(h) scalene triangle
Solution:
Question 13.
What letters of the English alphabet have reflectional symmetry about
(а) a vertical mirror
(b) a horizontal mirror
(c) both horizontal and vertical mirrors
Solution:
(a) The letters of English alphabet having reflectional symmetry about a vertical mirror are:
A, H, I, M, O, T, U, V, W, X, Y
(b) Letters of the English alphabets having reflectional symmetry about a horizontal mirror are:
B, C, D, E, H, I, O, X
(c) Letters of the English alphabet having reflectional of symmetry about vertical and horizontal mirror are:
O, X, I, H.