Dimensions 6996

The carpenter needs to make 4 wooden legs for the table, which have the shape of a regular 4-sided prism with dimensions of 9 cm × 9 cm × 60 cm. He will paint them all over with white paint. How many m² of surface must be painted?

Correct answer:

S =  0.9288 m²

Step-by-step explanation:

$$\begin{gathered} a=9\text{cm}\to \text{m}=9:100\text{m}=0.09\text{m} \\ b=a=0.09=\frac{9}{100}=0.09\text{m} \\ c=60\text{cm}\to \text{m}=60:100\text{m}=0.6\text{m} \\ {S}_1=2\cdot (a\cdot b+b\cdot c+a\cdot c)=2\cdot (0.09\cdot 0.09+0.09\cdot 0.6+0.09\cdot 0.6)=0.2322{\text{m}}^2 \\ S=4\cdot S_1=4\cdot 0.2322=0.9288{\text{m}}^2 \end{gathered}$$

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