6. Area of a rectangle and the area of a circle are equal. If the dimensions of the rectangle are 14 cm × 11 cm, then radius of the circle is
(a) 21 cm
(b) 10.5 cm
(c) 14 cm
(d) 7 cm
Area of rectangle = \(14 \times 11 = 154\, \text{cm}^2\).
Let radius of circle = \(r\). Then, \(\pi r^2 = 154\).
\(r^2 = \dfrac{154}{\pi} \approx 49\).
\(r = 7\,\text{cm}\).