A ladder 13 metres long reaches a window of a building 12 metres above the ground. What is the distance of the foot of the ladder from the wall?
A
5 metres
B
12.5 metres
C
25 metres
D
1 metre
Correct Option:
A
Explanation
The ladder, wall and ground form a right-angled triangle. The ladder is the hypotenuse: 13² = 12² + x² 169 = 144 + x² x² = 25, so x = 5 metres. This is the familiar 5-12-13 Pythagorean triple.
