HomeLearn Fast select Course
Show Unit/ChapterChange UnitChange SubjectLast Menu
ICSE-VIII-Mathematics

20: Area of Trapezium and a Polygon Class 8 Maths

with Solutions - page 5
Qstn# C-6 Prvs-QstnNext-Qstn
  • #6
    The adjacent sides of a parallelogram are 21 cm and 28 cm. If its one diagonal is 35 cm; find the area of the parallelogram.
    Ans :
    First we find area of ΔABC,
    Sides are, a = 28 cm
    B = 35 cm
    And c = 21 cm
    S = (a + b + c)/2
    = (28 + 35 + 21)/2
    = 84/2
    = 42 cm
    ∵ Diagonal of ∥gm divides it into two equal parts.
    ∴ area of ∥gm = 2 × area of ΔABC
    = 2 × 294
    = 588 cm2