Answer:
4 meters
Explanation:
Let the height at which the top of the ladder is be represented by h. The sketch of the question forms a right angled triangle. So that applying the Pythagoras rule,
=
+

=
+

25 =
+ 9
= 25 - 9
= 16
⇒ h =

= 4
Therefore, the height at which the top of ladder is placed is 4 meters.