Page 218 - ICSE Math 6

AT A GLANCE

¾ Two-dimensional objects or figures whose one half is of exactly the same size and shape as the
other half are known as symmetric figures.

¾ Any figure which is symmetrical about a line passing through it is said to have linear symmetry.
¾ Axis or line of symmetry is the line about which a figure is symmetric.
¾ All figures are not symmetric and a figure, if symmetric, can have finite or infinite lines of symmetry.

MENTAL MATHS

1. Write True or False.
(a) A circle of radius 6 cm has 6 lines of symmetry.
(b) A line segment of any length has 1 line of symmetry.

(c) An equilateral triangle has 3 lines of symmetry.
(d) The letter T has 2 lines of symmetry.
(e) An arc has 2 lines of symmetry, each passing through its end points.

2. Which of the following figures are symmetric?
(a) (b) (c)

(d) (e) (f)

3. For each of the following figures, identify whether line m is a line of symmetry or not.

m
(a) (b) (c) m

m
m m
(d) (e) (f) m

PRACTICE TIME

1. Complete the following figures to obtain the symmetric figures about the dotted line.

(a) (b) (c)

(d) (e) (f)

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