Page 221 - Start Up Mathematics_7

A Original B Translation
(image of A)
Glide reflection is a motion consisting of a translation
followed by a reflection in a line parallel to slide arrow.

Reflection
C (image of B)

Example 1: Draw all possible lines of symmetry of English alphabets given below.

(a) A (b) C (c) E (d) T
(e) W (f) X (g) Z

Solution: (a) (b) (c) (d)

(e) (f) (g) Z has no line of symmetry.

Example 2: Copy the figures with punched holes. Draw the axes of symmetry so that if the figure
is folded along it, the holes and their halves coincide.

(a) (b) (c) (d)

Solution: The figures should be folded along the dotted lines for symmetry.

(a) (b) (c) (d)

Example 3: In the following figures, locate the position of the missing holes in order to make
them symmetrical about the dotted line.

(a) (b) (c) (d)

Solution: The location of the holes is shown by darkened circles.

(a) (b) (c) (d)

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