Page 195 - Maths Skills - 7

Symmetry 193

HOTS

1. Name three letters of the English alphabet (in order of occurrence) which have only line symmetry and three
which have only rotational symmetry.
2. Should a figure having 2 or more lines of symmetry also possess rotational symmetry? Does a figure having
rotational symmetry always have linear symmetry?

3. State which of the following pairs of figures are reflections and which are rotations?

(i) (ii) (iii) (iv)

Word Stock
Symmetry Rotation Reflection Shape Dimension
Mirror Image Fold Clockwise Anticlockwise Divide

Activity

Objective: This activity gives you an idea that an object or figure may have either
linear symmetry or rotational symmetry or both.

Materials Required: Tracing paper, glazed paper, a pencil, an eraser and allpins quadrilateral
Procedure: 1. Draw or trace quadrilateral as shown in Fig. 1, on a glazed paper Fig. 1
and cut it.

2. Place the quadrilateral on a plain paper and trace the outline as
shown in Fig. 2. Fig. 2

3. Fix an allpin at point M and rotate the paper clockwise so that
MP falls on MN as shown in Fig. 3.
Fig. 3
4. Similarly, rotate the quadrilateral again edge to edge to obtain a
symmetrical design as shown in Fig. 4.

5. Now record the symmetry of each shape in the given table:
Fig. 4
Shape Order of Symmetry

Quadrilateral

Square

Leaf

Triangle