Mathematics
Assertion (A) : A parallelogram has a rotational symmetry of order 2 about the point of intersection O of its diagonals.
Reason (R) : A plane figure is said to have rotational symmetry if it aligns with the original position only once while being rotated about 360°.
Both A and R are correct, and R is the correct explanation for A.
Both A and R are incorrect.
A is true, but R is false.
A is false, but R is true.
Answer
A parallelogram has rotational symmetry of order 2, meaning it looks identical after a 180-degree rotation around its center.
So, assertion (A) is true.
A figure has rotational symmetry if it looks the same after being rotated by some angle less than 360 degrees, not just once.
So, reason (R) is false.
∴ A is true, but R is false.
Hence, option 3 is the correct option.
Related Questions
Assertion (A) : A shape (say circle) can be rotated from one position to another about it centre.
Reason (R) : Rotation is defined by (i)the angle of rotation, (ii) the direction of rotation and the centre of rotation.
Both A and R are correct, and R is the correct explanation for A.
Both A and R are correct, and R is not the correct explanation for A.
A is true, but R is false.
A is false, but R is true.
Assertion (A) : An equilateral triangle has a point of symmetry.
Reason (R) : A plane figure is said to have a point symmetry about a point, if every line segment drawn in the given figure passing through it is bisected by this point.
Both A and R are correct, and R is the correct explanation for A.
Both A and R are correct, and R is not the correct explanation for A.
A is true, but R is false.
A is false, but R is true.
Construct a triangle PQR in which:
QR = 4.6cm, Q = ∠R = 50°.
Draw all its lines of symmetry.
Construct a triangle ABC in which:
AB = BC = 4 cm and ∠ABC = 60°.
Draw all its lines of symmetry.