???????????? wot cha lookin for ????????? kosine law is c^2=a^2+b^2 -2ab *kosine (angel tween a & b)... c=the side kross from the angel... yu giv angel, b, & c....so me ges yu want a... c^2=20^2=400... b^2=12^2=144... kosine(55 deg)=0.573576436....... a^2=c^2-b^2 +2ab*0.573576436... ....=400 -144 +2*12*a*0.573576436... 24*0.573576436=13.76583447 a^2 -13.76583447a -256=0... quadratik equashun giv roots=24.3005677 or -10.5347333... thro awae the negativ...side leng gotta be > 0