Question 509236
The formula for perimeter is:
{{{ P = 2W + 2L }}}
The formula for area is:
{{{ A = L*W }}}
given:
{{{ A = 320 }}} cm2
(1){{{ L = 5W }}}
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(2) {{{ 320 = L*W }}}
(2) {{{ L = 320/W }}}
Substitute (2) into (1)
{{{ 320/W = 5W }}}
{{{ 320 = 5W^2 }}}
{{{ W^2 = 64 }}}
{{{ W = 8 }}}
and, since
{{{ L = 5W }}}
{{{ L = 40 }}}
The length is 40 cm and the width is 8 cm
so, the perimeter is
{{{ P = 2W + 2L }}}
{{{ P = 2*8 + 2*40 }}}
{{{ P = 16 + 80 }}}
{{{ P = 96 }}} cm