Stool cover fabric

Susan has an old stool shaped like a cube with an edge length of 80 cm. She wants to sew a new cover for it. How many square metres of fabric does she need, allowing an extra 15% for stitching and folds?

Final Answer:

S =  4.416 m²

Step-by-step explanation:

$$\begin{gathered} a=80\text{cm}\to \text{m}=80:100\text{m}=0.8\text{m} \\ q=100\%+15\%=1+\frac{15}{100}=1.15 \\ {S}_1=6\cdot a^2=6\cdot 0.8^2=\frac{96}{25}=3.84{\text{m}}^2 \\ S=q\cdot S_1=1.15\cdot 3.84=4.416{\text{m}}^2 \end{gathered}$$

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