Potrzebuję 3 zadania na już.

Potrzebuję 3 Zadania Na Już class=

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