Here is a rectangle ABCD. A B 20 cm 30 cm The length of the rectangle is increased by 10%. The wi

Question

Here is a rectangle ABCD.
A
B
20 cm
30 cm
The length of the rectangle is increased by 10%.
The width of the rectangle is increased by 5%.
Find the percentage increase in the perimeter of the rectangle.

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Nem 4 years 2021-08-17T19:16:41+00:00 1 Answers 747 views 1

Answers ( )

  1. thuhuong
    0
    2021-08-17T19:18:11+00:00
    Reply

    Answer: 8%

    Step-by-step explanation:

    Original Perimeter of the rectangle is:

    = 2 * ( Length * Width)

    = 2 * (20 + 30)

    = 100 cm

    The length increased by 10%. It therefore increased to:

    = 30 * ( 1 + 10%)

    = 30 * 1.1

    = 33 cm

    The width increased by 5%. It increased to:

    = 20 * ( 1 + 5%)

    = 21 cm

    New Perimeter is therefore:

    = 2 * ( 33 + 21)

    = 108 cm

    Percentage increase in perimeter is:

    = (New perimeter – old) / old perimeter

    = (108 – 100) / 100

    = 8%

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