Question

    Find out the circumference of a sector whose radius is 7

    cm and it makes the angle of 45° at the centre?
    A 19.5 cm Correct Answer Incorrect Answer
    B 17.5 cm Correct Answer Incorrect Answer
    C 14 cm Correct Answer Incorrect Answer
    D 15 cm Correct Answer Incorrect Answer

    Solution

    Radius = AO = BO = 7 cm Length of arc AB = Circumference of circle × (angle of sector)/360 = 2πr × (45°)/(360°) = 2 × 22/7 × 7 × (45°)/(360°) = 5.5 cm Circumference of sector= arc AB + 2 × radius = 5.5 + 7 + 7 = 19.5cm.

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