ICSE Guess > ICSE/ISC eBooks > Class X > Maths by Mr. M. P. Keshari

ICSE / ISC eBooks

Symmetry of Geometrical Figures

Line : - A line has an infinite number of lines of symmetry all perpendicular to it.

Line segment : - A line segment has two lines of symmetry :-

1. Its perpendicular bisector and
2. The segment itself.

Angle : - The angle bisector is the line of symmetry of an angle.

Isosceles Triangle : - The perpendicular bisector of the base of an isosceles triangle is the line of symmetry.

Equilateral Triangle : - The equilateral tiangle has three lines of symmetry – the bisectors of the angles.

Isosceles Trapezium : - An isosceles Trapezium has one line of symmetry, the perpendicular bisectors of parallel sides.

Rectangle : - A rectangle has two lines of symmetry the perpendicular bisectors of each pair of opposite sides.

Rhombus : - A rhombus has two lines of symmetry, the two diagonals.

Square : - A square has four lines of symmetry. (i) is two diagonals and (ii) two perpendicular bisectors of opposite sides.

Kite and arrow head : - A kite has one line of symmetry, its one diagonal.

Parallelogram : - A parallelogram has no line of symmetry.

Circle : - A circle has infinite number of line symmetry, its diameter.

Regular pentagon : - It has five lines of symmetry they are perpendiculars from vertex to the opposite base.

Regular Hexagon :- It has six lines of symmetry

1. Three digonals
2. Three perpendicular bisectors of opposite sides.