(i) True
(ii) True
(iii) True
(iv) False
A rhombus is symmetrical about both of its diagonals.
So, a rhombus has two lines of symmetry.
(v) True
A square is symmetrical about both of its diagonals and both the lines joining the midpoints of its opposite sides.
So, a square has four lines of symmetry.
(vi) True
A rectangle is symmetrical about both the lines joining the midpoints of its opposite sides.
So, a rectangle has two lines of symmetry.
(vii) True
Each one of the letters, H, I, O and X, of the English alphabetic system is symmetrical about its horizontal and vertical line, in the middle of the letters.
So, all these letters have two lines of symmetry.