the sum of the lengths of three sides of a rectangle is 55cm. each side is a whole number of a cl in length. the length is 8 cm more than the width. find the perimeter of the rectangle in cm

Respuesta :

Answer:

Given that,

the sum of the lengths of three sides of a rectangle is 55cm

each side is a whole number

the length is 8 cm more than the width

we get,

Let l be the length and b be the width,

[tex]l=b+8[/tex]

Also we have either

[tex]55=l+2b-----(1)[/tex]

or,

[tex]55=2l+b------(2)[/tex]

Substitute the value of l, in the equation (1), we get

[tex]55=8+b+2b[/tex][tex]55=3b+8[/tex][tex]3b=55-8[/tex][tex]3b=47[/tex][tex]b=\frac{47}{3}[/tex]

we get, b is not a whole number, Hence this is not possible.

Consider the equation (2), we get

[tex]55=2l+b[/tex][tex]55=2(b+8)+b[/tex][tex]55=2b+16+b[/tex][tex]3b=55-16[/tex][tex]3b=39[/tex][tex]b=13[/tex]

Perimeter of the rectangle is,

[tex]2(l+b)[/tex]

we get,

[tex]=2(b+8+b)=2(2b+8)[/tex][tex]=4b+16[/tex]

substitute b=13 cm, we get

[tex]=(4\times13)+16[/tex][tex]=68[/tex]

Perimeter of the rectangle is 68 cm.