$P_{czerwonego}=\pi \cdot {\left(8:2\right)}^2=\pi \cdot 4^2=16\pi c{m}^2$

$P_{zielonego}=\pi \cdot {\left(16:2\right)}^2-16\pi =\pi \cdot 8^2-16\pi =64\pi -16\pi =48\pi c{m}^2$

$P_{\dot{z}\acute{o}łtego}=\pi \cdot {\left(32:2\right)}^2-\pi \cdot {\left(16:2\right)}^2=\pi \cdot {16}^2-\pi \cdot 8^2=256\pi -64\pi =192\pi c{m}^2$