State whether the following statements are true or false:

(i) A rectangle is a regular quadrilateral.

(ii) A rhombus is a regular quadrilateral.

(iii) Every parallelogram is a rhombus.

(iv) The diagonals of a rhombus intersect at right angles.

(v) A polygon having 6 sides is called an octagon.

(vi) A road roller has two plane circular faces and one curved face.

(vii) A rectangular pyramid has 5 rectangular faces.

(i) False
Reason — A regular quadrilateral has all sides equal and all angles equal. A rectangle has all angles equal (90° each) but not all sides equal. So a rectangle is not a regular quadrilateral.

(ii) False
Reason — A rhombus has all sides equal but its angles are not necessarily equal. So a rhombus is not a regular quadrilateral.

(iii) False
Reason — A parallelogram has both pairs of opposite sides equal but not all sides equal in general. A rhombus has all four sides equal. So every parallelogram is not a rhombus.

(iv) True
Reason — The diagonals of a rhombus always intersect each other at right angles.

(v) False
Reason — A polygon with 6 sides is called a hexagon, not an octagon. An octagon has 8 sides.

(vi) True
Reason — A road roller is in the shape of a cylinder, which has two plane circular faces and one curved face.

(vii) False
Reason — A rectangular pyramid has 1 rectangular base and 4 triangular faces, making 5 faces in total. Only 1 face is rectangular, not all 5.