Question

If the perimeter of a rectangular garden plot is 80 metres, which of the following could be the length of one of its sides? i. 30 metres ii. 40 metres iii. 50 metres

Answer 1

30×2 =60m . Therefore it is the correct answer.
50 is wrong answer because 50×2=100m which exceeds 80.
similarly 40 is also wrong because 40×2= 80. so its other 2 sides will be 0 which is not possible.

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Answer 2

perimeter of rectangle =2(l+b)

here ,2(l+b)=80

as,we know that the side of rectangle is must be smaller than perimeter of any polygon.

now , according in this.

lengthy of side must be smaller .

so, the length of both corresponding 1)30 *2=60

2) """"""""""""""|""""""40*2=80

3)""'""""""""""""|""""""""""""50*2=100

here 1) option satisfied the answer smaller than perimeter

andA/c 2) option is equal to perimeter of rectangle which is never possible then here two side have 0 lengthy then rectangle could not be satisfied.

3) option this option also not satisfied the answer it is bigger than perimeter

so we can say that 1) 30 will be answer .

hope it help.

@rajukumar