Odpowiedź :
1.
[tex]P_{c}= 54 \ cm^{2}\\oraz\\P_{c} = 6a^{2}\\\\6a^{2} = 54 \ \ /:6\\\\a^{2} = 9\\\\a = \sqrt{9}\\\\\boxed{a = 3 \ cm}[/tex]
2.
[tex]h = 4\\r = \frac{h}{2} = 2\\V = ?\\\\V = \pi r^{2}h\\\\V = \pi \cdot2^{2}\cdot 4\\\\V = \pi \cdot4\cdot4\\\\\boxed{V = 16\pi \ j^{3}}[/tex]
3.
a - krawędź szescianu
D = 3
Pc = ?
[tex]D = 3\\oraz\\D = a\sqrt{3}\\\\a\sqrt{3} = 3 \ \ /:\sqrt{3}\\\\a = \frac{3}{\sqrt{3}}\cdot\frac{\sqrt{3}}{\sqrt{3}} = \frac{3\sqrt{3}}{3} = \sqrt{3}\\\\\\P_{c}= 6a^{2}\\\\P_{c} = 6\cdot(\sqrt{3})^{2}\\\\P_{c} = 6\cdot3\\\\\boxed{P_{c} = 18 \ j^{2}}[/tex]
Zad. 1
a - krawędź
Pc = 54cm2
Pc = 6a²
54 = 6a²
a² = 9
a = 3
Zad. 2
V = Pp * H
a - bok ; a = 4
Pp = πr²
r = 0,5a = 0,5*4 = 2
Pp = πr² = π*2² = 4π
H = a = 4
V = 4π * 4 = 16π ≅ 50,24
Zad. 3
d = 3
a²+(a√2)²=3²
a²+2a²=9
3a²=9
a²=3
a = √3
Pc = 6a² = 6*√3² = 6*3 = 18