NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.3 (Rationalised Contents)
NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.3 are the part of NCERT Solutions for Class 7 Maths (Rationalised Contents). Here you can find the NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.3.
 NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.1
 NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.2
 NCERT Solutions for Class 7 Maths Chapter 12 Symmetry Ex 12.3
Ex 12.3 Class 7 Maths Question 1.
Name any two figures that have both line symmetry and rotational symmetry.
Solution:
An equilateral triangle and a square both have line symmetry and rotational symmetry.
Ex 12.3 Class 7 Maths Question 2.
Draw, wherever possible, a rough sketch of
(i) a triangle with both line and rotational symmetries of order more than 1.
(ii) a triangle with only line symmetry and no rotational symmetry of order more than 1.
(iii) a quadrilateral with a rotational symmetry of order more than 1 but not a line symmetry.
(iv) a quadrilateral with line symmetry but not a rotational symmetry of order more than 1.
Solution:
(i) An equilateral triangle has 3 lines of symmetry and rotational symmetry of order 3.
(iii) A parallelogram has rotational symmetry of order 2 and no line of symmetry.
(iv) An isosceles trapezium has one line of symmetry and no rotational symmetry.
Ex 12.3 Class 7 Maths Question 3.
If a figure has two or more lines of symmetry, should it have rotational symmetry of order more than 1?
Solution:
Ex 12.3 Class 7 Maths Question 4.
Fill in the blanks:
Shape  Centre of Rotation  Order of Rotation  Angle of Rotation 
Square 



Rectangle 



Rhombus 



Equilateral triangle 



Regular hexagon 



Circle 



Semicircle 



Solution:
Shape  Centre of Rotation  Order of Rotation  Angle of Rotation 
Square  Point of intersection of diagonals  4  90° 
Rectangle  Point of intersection of diagonals  2  180° 
Rhombus  Point of intersection of diagonals  2  180° 
Equilateral triangle  Point of intersection of medians  3  120° 
Regular hexagon  Point of intersection of diagonals  6  60° 
Circle  Centre  Infinite  Every angle 
Semicircle  Centre  1  360° 
Ex 12.3 Class 7 Maths Question 5.
Name the quadrilaterals which have both line and rotational symmetry of order more than 1.
Solution:
A square, a rectangle and a rhombus are such quadrilaterals which have both line and rotational symmetry of order more than 1.
Ex 12.3 Class 7 Maths Question 6.
After rotating by 60° about a centre, a figure looks exactly the same as its original position. At what other angles will this happen for the figure?
Solution:
Since the figure looks exactly the same as its original position, when rotated through 60° about its centre, the angle of rotation is 60°. If the figure is rotated through the angles 120°, 180°, 240°, 300° and 360°, it looks exactly the same.
Ex 12.3 Class 7 Maths Question 7.
Can we have a rotational symmetry of order more than 1 whose angle of rotation is
(i) 45°?
(ii) 17°?
Solution:
(i) Yes; because 360° is divisible by 45°.
(ii) No; because 360° is not divisible by 17°.
Related Links:
NCERT Solutions for Maths Class 8
NCERT Solutions for Maths Class 9
NCERT Solutions for Maths Class 10