Greenhouse

The Garden plastic greenhouse is shaped like a half-cylinder with a diameter of 6 m and a base length of 20 m. At least how many m² of plastic is needed for its cover?

Correct answer:

S =  216.8 m²

Step-by-step explanation:

$$\begin{gathered} D=6\text{m} \\ l=20\text{m} \\ r=D/2=6/2=3\text{m} \\ S=\pi \cdot r^2+\pi \cdot r\cdot l=3.1416\cdot 3^2+3.1416\cdot 3\cdot 20=216.8{\text{m}}^2 \end{gathered}$$

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