Since the base(The ground) is perpendicular to the wall it forms a right angle and since the ladder is placed over the window it orms a triangle/Right angle triangle
By using the right hypotenuse side theoram-
a^2 + b^2 = c^2
In this condition the hypotenuse (17) and the base (8) is given
8^2 + b^2 =17^2
64 + b^2 = 289
b^2 =289 - 64
b^2=225
b=√225
b=15
Thus the height from the ground to the window is 15
