The shaded part is \( \dfrac{1}{3} \) of the smaller circle's area.<br><br>&bull; Smaller circle: radius = 21 cm.<br>&bull; Area of smaller circle = \( \pi r^2 = \dfrac{22}{7} \times 21 \times 21 = 1386 \) cm&sup2;.<br>&bull; Shaded area = \( \dfrac{1}{3} \times 1386 = 462 \) cm&sup2;.<br><br>Final Answer: 462 cm&sup2;