Pyramid-shaped 7820

The pyramid-shaped tent has a square base with a side size of 2.2m and a height of 1.8m. How many square meters of tent canvas are needed to make it if we count an extra five percent for the foundation?

Correct answer:

S =  14.8279 m²

Step-by-step explanation:

$$\begin{gathered} a=2.2\text{m} \\ h=1.8\text{m} \\ s=\sqrt{h^2+(a/2{)}^2}=\sqrt{1.8^2+(2.2/2{)}^2}\doteq 2.1095\text{m} \\ {S}_1=a\cdot s/2=2.2\cdot 2.1095/2\doteq 2.3205{\text{m}}^2 \\ S=1.05\cdot (a^2+4\cdot S_1)=1.05\cdot (2.2^2+4\cdot 2.3205)=14.8279{\text{m}}^2 \end{gathered}$$

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