3. A 15 m long ladder reached a window 12 m high from the ground on placing it against a wall at a distance a. Find the distance of the foot of the ladder from the wall.
Here. As we can see, The ladder with wall forms a right-angled triangle with
the vertical height of the wall = perpendicular = 12 m
length of ladder = Hypotenuse = 15 m
Now, As we know
In a Right-angled Triangle: By Pythagoras Theorem,
Hence the distance of the foot of the ladder from the wall is 9 m.