We can use the next diagram in order to solve the question
we need to find x, x is the distance from the house to the foot of the ladder, we will use a trigonometric function in order to find x in this case we will use the cosine
where
θ= 60°
AS=x
H=15 ft
we substitute the values
we need to isolate the x
the distance from the house to the foot of the ladder is 7.5 ft