if put rite angel at bottom left, hite=leng av left side (up from base)... hite=13... yu mite put 35 deg angel at bottom or top...get differ triangels... if 35 deg at bottom rite, hite/diagonal=sine(35 deg)=0.573576436... diagonal=hite/0.573576436=1.743446796*13=22.66480834... then, base=diagonal*kosine(35 deg)=22.66480834*0.819152044... base=18.56592409... Other wae...yuze 55 deg angel at bottom