According to the diagram and the information given, to find the length of the ladder we can use trigonometric ratios. More specifically, we need to use sine, which is the ratio between the opposite leg to a given angle and the hypotenuse.
In this case, the given angle is 63° and the opposite leg to it is 15. Use these values to find the hypotenuse of the triangle formed, which is the length of the ladder.
The length of the ladder is 16.8 ft