You can
put this solution on YOUR website!I am guessing that the short lenghts are congruent. (Insuffice)
one short length = s
other short length = t
long side = l
st = 5l which can look like: st/5 = l
s + t + l = 28
s + t + st/5 = 28 remember ~> s = t
s + s + s^2/5 = 28
s^2/5 + 2s - 28 = 0
s^2 + 10s - 140 = 0 You can finish the rest.
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