Answer:
15 ft
Explanation:
We can represent the situation with the following figure
Therefore, the length of the ladder is the hypotenuse of the right triangle formed, where the legs are 12 ft and 9 ft. Using the Pythagorean theorem, we can calculate the length of the ladder as
[tex]\begin{gathered} Ladder=\sqrt{12^2+9^2} \\ Ladder=\sqrt{144+81} \\ Ladder=\sqrt{225} \\ Ladder=15 \end{gathered}[/tex]Therefore, the length of the ladder is 15 ft
