In the given figure, AB, AE, EF, FG and GB are semicircles. AB = 56 cm and AE = EF = FG = GB. What is the area (in cm2) of the shaded region?

Answer: Option D

AB = 56 cm
AE = EF = FG = GB = 14 cm
∴ EM = MF = 7 cm
PF = $$\frac{56}{2}$$ = 28 cm
OF = 28 - r
OM = 7 + r
MF = 7
In ΔOMF,
OM² = OF² + MF²
(7 + r)² = (28 - r)² + 7²
49 + r² + 14r = 784 + r² - 56r + 49
70r = 784
r = $$\frac{784}{70}$$ = 11.2
Area of circle = πr²
= $$\frac{22}{7}\times \frac{112}{10}\times \frac{112}{10}$$
= 394.24 cm²