the pythagorean theorm is for rite triangels
in jenral, triangel area=base*hite
for area=10, base*hite=20
1 possabel wae is 5*4...base=5 & hite=4 or the other wae around
then the long side is root av sum av squares...25+16=41
root(41)=6.403124237
distans around=rim length=4+5+6.40312...
=15.403124237