## ML Aggarwal Class 8 Solutions for ICSE Maths Chapter 16 Symmetry Reflection and Rotation

Question 1.

Draw the line or lines of symmetry, if any, of the following shapes and count their number :

Solution:

Question 2.

For each of the given shape in question 1, find the order of the rotational symmetry (if any).

Solution:

(i) None

(ii) None

(iii) Two

(iv) Four

(v) Three

(vi) Four

Question 3.

Construct a rectangle ABCD such that AB = 4.5 cm and BC = 3 cm. Draw its line (or lines) of symmetry.

(i) Draw a line AB = 4.5 cm.

(ii) Draw a line BQ from point B making an angle of 90°.

(iii) Taking B as centre and radius = 3 cm,

mark an arc on BQ, name it as C.

(iv) As we know, opposite sides of rectangle are equal.

Therefore from point C. As a centre and radius = 4.5 cm,

draw an arc and with A as centre and 3 cm as radius,

make another as C, cutting the previous arc at point D.

(v) Join DC and DA.

(vi) ABCD is a required rectangle.

Lines of symmetry:

It has 2 lines of symmetry,

the lines joining the midpoints of opposite sides.

Question 4.

Construct a rhombus ABCD with AB = 5.3 cm and ∠A = 60°. Draw its line (or lines) of symmetry.

Solution:

(i) Draw line segment AB = 5.3 cm.

(ii) Construct ∠BAX = 60°.

(iii) With A as centre, radius = 5.3 cm draw an arc on AX.

(iv) Mark the point of intersection = D.

(v) With D as the centre and radius = 5.3 cm, draw an arc.

(vi) With B as centre and same radius,

draw another arc, such that it intersects the previous at C.

(vii) Join CD and CB.

ABCD is a required rhombus.

Lines of symmetry in rhombus = 2,

the diagonals of the rhombus.