A round dining-table top has a diameter of 42 cm. What is the area of the top? Take $\pi = \frac{22}{7}$.

Explanation

1. 01

   Radius = $42 \div 2 = 21$ cm.

2. 02

   Area = $\pi r^2 = \frac{22}{7} \times 21 \times 21 = 1386$ cm².