Answer:
[tex]\large\boxed{V=\dfrac{2}{9}s^3}[/tex]
Step-by-step explanation:
[tex]\text{The formula of a volume of a pyramid:}\\\\V=\dfrac{1}{3}BH\\\\B-base\ area\\H-height\\\\\text{The base of the pyramid os athe square with side length}\ s.\\\text{Therefore the base area}\ B=s^2.\\\\\text{The height of the pyramid is}\ \dfrac{2}{3}\ \text{that of it's side:}\ H=\dfrac{2}{3}s.\\\\\text{Substitute:}\\\\V=\dfrac{1}{3}(s^2)\left(\dfrac{2}{3}s\right)=\dfrac{2}{9}s^3[/tex]
