📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!

    Question

    In a circle with centre O, ABC is a secant intersecting

    the circle at A and B and DC is a tangent to the circle at D. If DC = 12 cm and BC = 6 cm, then the length of AB is equal to:
    A 20 cm Correct Answer Incorrect Answer
    B 18 cm Correct Answer Incorrect Answer
    C 22 cm Correct Answer Incorrect Answer
    D 16 cm Correct Answer Incorrect Answer

    Solution

    ATQ,

    We have, ⇒ DC = 12 cm and BC = 6 cm ⇒ DC2 = BC × (BC + AB) ⇒ 122 = 6 × (6 + AB) ⇒ 144 = 6 × (6 + AB) ⇒ 144 = 36 + 6AB ⇒ 144 - 36 = 6AB ⇒ 108 = 6AB ⇒ AB = 108 / 6 ⇒ AB = 18 cm ∴ The length of AB is 18 cm.

    Practice Next
    More Previous year papers Questions

    Relevant for Exams:

    ask-question