Find the square root of 31-4√21

31+4

21

=28+3+2

4×21

=(

28

)

2

+(

3

)

2

+2

28

×

3

=(

28

+

3

)

2

Using (a+b)

2

=a

2

+b

2

+2ab

31+4

21

=(

28

+

3

)

2

∴

31+4

21

=(

28

+

3

)

The square root of

31+4

21

is (

28

+

3

)

the smallest possible measurement of the width is 14 feet

step-by-step explanation:

let's assume length of parallelogram is 'l'

width of parallelogram is 'w'

the perimeter of a parallelogram must be no less than 40 feet

so, we get

we are given

length of parallelogram is 6 feet

so,

l=6

we can plug it

now, we can solve for w

subtract both sides by 12

divide both sides by 2

and we get

so,

the smallest possible measurement of the width is 14 feet