Pyramid of Giza

The Great Pyramid of Giza is shaped like a regular quadrangular pyramid. The base edge is 227 m long, and the pyramid is 140 m high. What is the weight of the stone needed to build this pyramid if the weight of 1 m³ of stone is 2.5 t?

Correct answer:

m =  6011717 t

Step-by-step explanation:

$$\begin{gathered} a=227\text{m} \\ h=140\text{m} \\ \rho =2.5{\text{t/m}}^3 \\ S=a^2=227^2=51529{\text{m}}^2 \\ V=\frac{1}{3}\cdot S\cdot h=\frac{1}{3}\cdot 51529\cdot 140\doteq 2404686.6667{\text{m}}^3 \\ m=\rho \cdot V=\rho \cdot \frac{7214060}{3}=6011717\text{t} \end{gathered}$$

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