Question

    The side of an equilateral triangle is 28 cm. Taking

    each vertex as the centre, a circle is described with a radius equal to half the length of the side of the triangle. Find the area of that part of the triangle which is not included in the circles (use π = 22/7 and  √3 = 1.73).
    A 30.89 cm² Correct Answer Incorrect Answer
    B 38.08 cm² Correct Answer Incorrect Answer
    C 31.08 cm² Correct Answer Incorrect Answer
    D 39.08 cm² Correct Answer Incorrect Answer

    Solution

    Given: Side of equilateral triangle = 28 cm
    Radius of each circle = 14 cm (half of 28 cm)
    π = 22/7, √3 = 1.73 Area of triangle = (√3 / 4) × a²
    = (1.73 / 4) × 28² = 1.73 × 196 = 339.08 cm² Area of one sector = (60/360) × π × r²
    = (1/6) × (22/7) × 14² = (1/6) × (22/7) × 196 ≈ 102.67 cm²
    Total area of 3 sectors = 3 × 102.67 = 308.01 cm² Required area = 339.08 − 308.01 = 31.07 cm²

    Practice Next

    Relevant for Exams: