The figure is made up of a small semicircle of diameter 21 cm and a large semicircle of radius 21 cm. Find its perimeter and area. (Take π = 22.)

Площадь малого полукруга:

\[\frac{1}{2} \cdot π \cdot r^2 = \frac{1}{2} \cdot \frac{22}{7} \cdot (10.5)^2 = \frac{1}{2} \cdot \frac{22}{7} \cdot 110.25 = \frac{11}{7} \cdot 110.25 = 173.25 \text{ см}^2\]

Площадь большого полукруга:

\[\frac{1}{2} \cdot π \cdot r^2 = \frac{1}{2} \cdot \frac{22}{7} \cdot (21)^2 = \frac{1}{2} \cdot \frac{22}{7} \cdot 441 = \frac{11}{7} \cdot 441 = 693 \text{ см}^2\]

Периметр малого полукруга:

\[π \cdot r + 2r = \frac{22}{7} \cdot 10.5 + 2 \cdot 10.5 = \frac{22}{7} \cdot 10.5 + 21 = 33 + 21 = 54 \text{ см}\]

Периметр большого полукруга:

\[π \cdot r + 2r = \frac{22}{7} \cdot 21 + 2 \cdot 21 = \frac{22}{7} \cdot 21 + 42 = 66 + 42 = 108 \text{ см}\]