Let missing one be x
If both are similar
[tex]\\ \sf\longmapsto \dfrac{20}{25}=\dfrac{16}{x}[/tex]
[tex]\\ \sf\longmapsto \dfrac{4}{5}=\dfrac{16}{x}[/tex]
[tex]\\ \sf\longmapsto 4x=16(5)[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{16(5)}{4}[/tex]
[tex]\\ \sf\longmapsto x=20[/tex]
