Answer
$h \approx 11.6$ ft
Work Step by Step
1. Find the length of the castle from the ground to the top of the ladder
Let $h =$ the height
$ h^{2} + b^{2} = c^{2}$
$h = \sqrt {c^{2} - b^{2}}$
$h = \sqrt {12^{2} - 3^{2}}$
$h = \sqrt {135}$
$h = 11.618...$ ft
$h \approx 11.6$ ft
