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    Question

    The area of a circle is 1.54 cm2. Find the

    perimeter of the minor sector that is subtended by an angle of 90o. (take π = 22/7)
    A 2.5 cm Correct Answer Incorrect Answer
    B 1.5 cm Correct Answer Incorrect Answer
    C 3 cm Correct Answer Incorrect Answer
    D 2.8 cm Correct Answer Incorrect Answer

    Solution

    Area of circle = π X radius2

    So, 1.54 = (22/7) X radius2

    So, 0.49 = radius2

    So, radius = 0.7 cm (Since radius cannot be negative, we may discard the negative value of root)

    Perimeter of sector = 2 X radius of the circle + length of the arc

    Length of minor arc = (θ/360o) X 2 X π X radius

    So, length of the minor arc of the given circle = (90o/360o) X 2 X (22/7) X 0.7 = 1.1 cm

    So, perimeter of the sector = 1.1 + (2 X 0.7) = 2.5 cm

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