ICSE-VIII-Mathematics

20: Area of Trapezium and a Polygon Class 8 Maths

with Solutions - page 3
Qstn# B-12-i Prvs-QstnNext-Qstn
  • #12-i
    perimeters of the original rectangle and the resulting rectangle. (ii) areas of the original rectangle and the resulting rectangle. (ii) areas of the original rectangle and the resulting rectangle.
    Ans : Perimeter P = 2(x + y)
    Again, new length = 2x
    New breadth = 2y
    ∴ New perimeter P’ = 2(2x + 2y)
    = 4(x + y)
    = 2.2(x + y)
    = 2P
    ∴ P/P’ = ½
    i.e. P : P’
    = 1 : 2 (ii) Area A = xy
    New Area A’ = (2x)(2y) = 4xy
    = 4A
    ∴ A/A’ = ¼
    i.e., A : A’
    = 1 : 4 (ii) Area A = xy
    New Area A’ = (2x)(2y) = 4xy
    = 4A
    ∴ A/A’ = ¼
    i.e., A : A’
    = 1 : 4
  • #12-ii
    areas of the original rectangle and the resulting rectangle.
    Ans : Area A = xy
    New Area A’ = (2x)(2y) = 4xy
    = 4A
    ∴ A/A’ = ¼
    i.e., A : A’
    = 1 : 4