#### Answer

$110$ m

#### Work Step by Step

Since the triangles are similar, we can set up a proportion between the small and large triangle sides:
$\displaystyle \frac{n}{220~m}=\frac{50~m}{100~m}$
Cross-multiply and solve for $n$:
$100n=50*220$
$100n=11000$
$n=11000/100$
$n=110$ m