A building is 1 ft from a 10-ft fence that surrounds the property. A worker wants
to wash a window in the building 13 ft
from the ground. He plans to place a
ladder over the fence so it rests against
the building. (See the figure.) He
decides he should place the ladder 8 ft
from the fence for stability. To the
nearest tenth of a foot, how long a
ladder will he need?