Question

cine mă ajută va rog frumos​

Answer 1

R=5 cm

diagonala fata=1 dm= 10 cm=d

Inaltime baza:

$h_b=\frac{l\sqrt{3} }{2}$

$R=\frac{2}{3}\times h_b\\\\ 5=\frac{2}{3}\times \frac{l\sqrt{3} }{2} \\\\5=\frac{l\sqrt{3} }{3} \\\\l=\frac{15}{\sqrt{3} } =5\sqrt{3}\ cm$

• Aflam inaltimea prismei din Pitagora:

Inaltimea prismei o notam cu h

Vom avea din Pitagora:

d²=h²+l²

100=h²+75

h²=25

h= 5 cm

$A_l=P_b\times h$

$P_b=3\times l=15\sqrt{3} \ cm$

$A_l=15\sqrt{3} \times 5=75\sqrt{3} \ cm^2$

$V=A_b\times h$

$A_b=\frac{l^2\sqrt{3} }{4} =\frac{75\sqrt{3} }{4} \ cm^2$

$V=\frac{75\sqrt{3} }{4}\times 5=\frac{375\sqrt{3} }{4} \ cm^3$