In triangle ABC
AC = hypotenuse = length of ladder = 12 ft
BC = opposite = height on the wall of house = h
θ = angle of the ladder with the horizontal = 64 deg
using trigonometric formula
Sinθ = opposite/hypotenuse
Sinθ = BC/AC
Sinθ = h/L
Sin64 = h/12
h = 12 Sin64
h = 10.8 ft
since h > 10.5 ft (height of the window)
hence the ladder reach well above the window
