Question

    A ladder is resting on the ground with the top end in

    contact with the top of a wall of a height of 12 metres. If the length of the ladder is 13 metres, at what distance from the wall is the base of the ladder on the ground?
    A 7 metres Correct Answer Incorrect Answer
    B 10 metres Correct Answer Incorrect Answer
    C 5 metres Correct Answer Incorrect Answer
    D 8 metres Correct Answer Incorrect Answer

    Solution

    Height of the wall = 12 meters (vertical leg of the triangle) Length of the ladder = 13 meters (hypotenuse of the triangle) Distance of the ladder's base from the wall = ? (horizontal leg of the triangle) We can apply the Pythagorean Theorem: (Base)² + (Height) ² = (Hypotenuse) ² Let the base = x meters x² + 12² = 13² ⇒ x² + 144 = 169 ⇒ x² = 169 – 144 = 25 ⇒ x² = 25 ⇒ x = 5 m.

    Practice Next