New RBI Grade B 2025 Notification will come Soon! Enroll Here

    Question

    Find the length of the direct common tangent of two

    circles with radii 8 cm and 5 cm respectively, if the distance between their centres is 11 cm.
    A 2√7 cm Correct Answer Incorrect Answer
    B 5√7 cm Correct Answer Incorrect Answer
    C 4√7 cm Correct Answer Incorrect Answer
    D 17√7 cm Correct Answer Incorrect Answer

    Solution

    ATQ,

    Direct common tangent = √[(distance between centres)² − (difference of radii)²]

    = √[11² − (8 − 5)²]

    = √[121 − 9] = √112 = 4√7 cm

    Practice Next

    Relevant for Exams: