Draw a circle with radius 2.5 cm with the help of compass.
(i) By joining the ends of two diameters, we get a rectangle.
For example in the figure below we find AB = CD = 4 cm, BC = AD = 3 cm, i.e. pairs of opposite sides are equal and also ∠A=∠B=∠C=∠D=90∘, i.e. each angle is of 90. Hence, it is a rectangle.
(ii) If the diameters are perpendicular to each other, then by joining the ends of two diameters, we get a square. By measuring, we find that AB = BC = CD = DA = 3.5 cm (approx.), i.e. all four sides are equal. Also ∠A=∠B=∠C=∠D=90∘, i.e. each angle is of 90. Hence, it is a square.