#### Answer

b=$\sqrt 44$
b$\approx$6.633

#### Work Step by Step

$a^{2}$ +$b^{2}$ =$c^{2}$ Let a=10cm and c=12cm
$10^{2}$ +$b^{2}$ =$12^{2}$
100+$b^{2}$=144
$b^{2}$=144-100
$b^{2}$ =44
b=$\sqrt 44$
b$\approx6.633cm$
The length of the leg is exactly $\sqrt 44$ and approximately 6.33cm.