Sidewalk

Workers will pave a 1-meter-wide sidewalk in the garden with tiles around the block-shaped pool. In the picture, the sidewalk is shown in gray. The dimensions of the bottom of the pool are 8.5 meters and 6 meters. The height of the pool walls is 2 meters.

How many m² of pavement will be laid with tiles?

Correct answer:

S =  33 m²

Step-by-step explanation:

$$\begin{gathered} s=1\text{m} \\ a=8.5\text{m} \\ b=6\text{m} \\ c=2\text{m} \\ {S}_1=a\cdot b=8.5\cdot 6=51{\text{m}}^2 \\ {S}_2=(a+2\cdot s)\cdot (b+2\cdot s)=(8.5+2\cdot 1)\cdot (6+2\cdot 1)=84 \\ S=S_2-S_1=84-51=33{\text{m}}^2 \end{gathered}$$

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