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ICSE-VIII-Mathematics

20: Area of Trapezium and a Polygon Class 8 Maths

with Solutions -
Qstn# A-7 Prvs-QstnNext-Qstn
  • #7
    The area of an equilateral triangle is 144√3 cm2; find its perimeter.
    Ans : Let each side of an equilateral triangle = x cm
    ∴ Its area = √3/4 (side)2
    = √3/4 x2
    = 144√3 (given)
    ⇒ x2 = 144√3 × 4/√3
    ⇒ x2 = 144 × 4
    ⇒ x2 = 576
    ⇒ x = √576
    = 24 cm
    Each side = 24 cm
    Hence perimeter = 3(24) = 72 cm