[tex]1 \: L = 1000 \: {cm}^{3} [/tex]
[tex]V_{cub} = {l}^{3} = {50}^{3} = 125000 \: {cm}^{3} [/tex]
[tex]V_{apa} = 50 \: L = 50000 \: {cm}^{3} [/tex]
[tex]V_{apa} = {l}^{2} \times h[/tex]
[tex] {50}^{2} \times h = 50000 [/tex]
[tex]2500 \times h = 50000[/tex]
[tex]h = 50000 \div 2500[/tex]
[tex]h=20 \:cm[/tex]