
To find median $ m $ use formula:
$$ m = \frac{ a + b } { 2 } $$After substituting $a = 12\, \text{cm}$ and $b = 6\, \text{cm}$ we have:
$$ m = \frac{ 12\, \text{cm} + 6\, \text{cm} } { 2 } $$ $$ m = \frac{ 18\, \text{cm} } { 2 } $$ $$ m = 9\, \text{cm} $$