Răspuns:
Explicație pas cu pas:
a)
[tex] V_{cubului} = {l}^{3} \\ V_{cubului} = {4}^{3} = 4 \times 4 \times 4 = 16 \times 4 = \boxed{ {64 \: m}^{3} } \\ 1 \: {m}^{3} = 1000 \: l \\ 64 \: {m}^{3} = 64 \times 1000 \: l = \boxed{64000 \: l}[/tex]
[tex] = > a) - > 5[/tex]
b)
[tex] A_{ \square} = {l}^{2} = > 81 \: {m}^{2} = {l}^{2} \\ = > l = \sqrt{81 \: {m}^{2} } \\ = > l = 9 \: m \\ P_{ \square} = 4 \times l = > P_{ \square} = 4 \times 9 \: m = \boxed{36 \: m}[/tex]
[tex] = > b) - > 4[/tex]
c)
[tex] P_{dreptunghi} = 2 \times (L + l) = > 30 \: m = 2 \times (L + l) \\ l = L \div 2 = > L = 2 \times l \\ 2 \times (2 \times l + l) = 30 \: m \\ 2 \times 3 \times l = 30 \: m | \div 2 \\ = > 3 \times l = 15 \: m | \div 3 \\ = > \boxed{l = 5 \: m} \\ = > l = 5 \: m \times 2 \\ = > \boxed{L = 10 \: m}[/tex]
[tex] = > c) - > 3[/tex]
d)
[tex]dac \breve{a} \: AB \equiv \: AC \: \: \: BC > AB \: \: \: BC > AC = > \triangle \: ABC \: isoscel \\ P_{ \triangle} = l_{1} + l_{2} + l_{3} = > 72 \: m = AB + AC + 32 \: m \\ AB \equiv \: AC = > AB = AC \\ AB + AC = 72 \: m - 32 \: m \\ AB + AC = 40 \: m \\ AB = 40 \: m \div 2 \\ \boxed{AB = 20 \: m}= > \boxed{AC = 20 \: m}[/tex]
[tex] = > d) - > 1[/tex]
e)
[tex] V_{paralelipipedului} = L \times l \times h = > \\ = > V = 3 \: m \times 4 \: m \times 5 \: m \\ = > V = 12 \: m \times 5 \: m \\ = > \boxed{V = {60 \: m}^{3} }[/tex]
[tex] = > e )- > 2[/tex]
