I'm having a hard time with this question

A building is 3 it from a 9-ft fence that iation surrounds the property. A worker wants to wash a window in the building 14 ft from the ground. He plans to place a ladder over the fence so it rests against 5 ft the building. (See the figure.) He decides he should place the ladder 8 ft from the fence for stability. To the 9 n nearest tenth of a foot, how long a ladder will he need? He will need a it ladder. (Type an integer of decimal rounded to the nearest tenth as needed.)