$P_p=\frac{a^2\sqrt{3}}{4}=\frac{{\left(30\text{cm}\right)}^2\cdot \sqrt{3}}{4}=\frac{900\sqrt{3}{\text{cm}}^2}{4}=225\sqrt{3}{\text{cm}}^2$

 

$x^2+x^2={\left(30\text{cm}\right)}^2$  

$2x^2=900{\text{cm}}^2\mid ;2$ $2x^2=900{\text{cm}}^2\mid ;2$  

$x^2=450{\text{cm}}^2\mid \sqrt{}$  

$x=\sqrt{450}\text{cm}$  

$x=\sqrt{225\cdot 2}\text{cm}$  

$x=15\sqrt{2}\text{cm}$  

$h^2+{\left(15\text{cm}\right)}^2={\left(15\sqrt{2}\text{cm}\right)}^2$  

$h^2+225{\text{cm}}^2=225\cdot 2{\text{cm}}^2\mid -225{\text{cm}}^2$  

$h^2=450{\text{cm}}^2-225{\text{cm}}^2$  

$h^2=225{\text{cm}}^2\mid \sqrt{}$  

$h=15\text{cm}$  

 

$P_b=3\cdot \frac{1}{{\sout{2}}^1}\cdot {\sout{30}}^{15}\text{cm}\cdot 15\text{cm}=3\cdot 225{\text{cm}}^2=675{\text{cm}}^2$  

 

$P_c=225\sqrt{3}{\text{cm}}^2+675{\text{cm}}^2=225\left(\sqrt{3}+3\right){\text{cm}}^2$  

Odpowiedź:

Pole powierzchni całkowitej tego ostrosłupa to 225(√3+3) cm².