a)
[tex]\it \mathcal{A}_{lac}=\pi R^2=\pi\cdot10^2=100\pi\approx100\cdot3,141=314,1\ m^2[/tex]
b)[tex]\it \mathcal{A}_{DPM}=\mathcal{A}_{ABCD}-(\mathcal{A}_{PAD}+\mathcal{A}_{BPM}+\mathcal{A}_{DCM})=30\cdot20-\dfrac{20\cdot20+10\cdot10+30\cdot10}{2}=\\ \\ \\ =600-\dfrac{400+100+300}{2}=600-400=200\ m^2[/tex]
c)
[tex]\it \mathcal{A}_{gazon}=\mathcal{A}_{ABCD}=\mathcal{A}_{lac} \approx600-314,1 \Rightarrow \mathcal{A}_{gazon} \approx 285,9\ m^2<314,1\\ \\ Deci,\ \mathcal{A}_{gazon}<\mathcal{A}_{lac}[/tex]
