Exercise 17.1
Question 1: List any four symmetrical objects from your phone or school. Also, mention the line of symmetry.
Solution 1:
Question 2: Identify the symmetrical instruments from your mathematical instrument box.
Solution 2:
Question 3: Copy each of the following on a squared paper and compute them in such a way that the dotted line is the line of symmetry.
Solution 3:
Exercise 17.2
Question 1: Find the number of lines of symmetry in each of the following shapes.
Solution 1:
Question 2: Copy the following drawings on squared paper and complete each one of them in such a way that resulting figure has two dotted lines as two lines of symmetry:
Solution 2:
Exercise 17.3
Question 1: Complete the following table:
Solution 1:
Question 2: Consider the English alphabets A to Z. List among them the letters which have
(i) vertical line of symmetry. (like A)
(ii) horizontal lines of symmetry. (like B)
(iii) vertical and horizontal lines of symmetry. (like I)
(iv) no line of symmetry. (like Q)
Solution 2:
(i) Vertical line of symmetry. (like A)
(ii) Horizontal lines of symmetry. (like B)
(iii) Vertical and horizontal lines of symmetry. (like I)
(iv) No line of symmetry. (like Q)
Question 3: Can you draw a triangle having:
(i) exactly one line of symmetry
(ii) exactly two lines of symmetry.
(iii) three lines of symmetry.
(iv) no line of symmetry.
Solution 3:
(i) An isosceles triangle has exactly one line of symmetry.
(ii) No there is no triangle having exactly two lines of symmetry.
(iii) An equilateral triangle three lines of symmetry.
(iv) A scalene triangle has line of symmetry.
Question 4: On a squared paper, sketch the following:
(i) A triangle with a horizontal line of symmetry but no vertical line of symmetry.
(ii) A quadrilateral with both horizontal and vertical lines of symmetry.
(iii) A quadrilateral with a horizontal line of symmetry but no vertical line of symmetry.
(iv) A hexagon with exactly two lines of symmetry.
(v) A hexagon with six lines of symmetry.
Solution 4:
Question 5: Draw neat diagrams solving the line (or lines) of symmetry and give the specific name to the quadrilateral having:
(i) only one line of symmetry. How many such quadrilaterals are there?
(ii) its diagonals as the only lines of symmetry.
(iii) two lines of symmetry other than diagonals.
(iv) more than two lines of symmetry.
Solution 5:
(i) Only one line of symmetry.
(ii) Diagonals as the only lines of symmetry:- Rhombus
(iii) Two lines of symmetry other than diagonals:- Rectangle
(iv) More than two lines of symmetry:- Square
Question 6: Write the specific names of all the three quadrilaterals which have only one line of symmetry.
Solution 6:
Question 7: Trace each of the following figures and draw the lines of symmetry, if any:
Solution 7:
Question 8: On squared paper copy the triangle in each of the following figures. In each case draw the line(s) of symmetry if any and identify the type of the triangle.
Solution 8:
Question 9: Find the lines of symmetry for each of the following shapes:
Solution 9:
