a \(S=12^2\cdot3.14=452.16\left(cm^2\right)\)
b: \(S=0.5^2\cdot3.14=0.785\left(dm^2\right)\)
c: \(S=4.8^2\cdot3.14=72.3456\left(m^2\right)\)
d: \(S=1.2^2\cdot3.14=4.5216\left(m^2\right)\)
e: \(S=0.6^2\cdot3.14=1.1304\left(m^2\right)\)
f: \(S=1.4^2\cdot3.14=6.1544\left(m^2\right)\)