How can i get solution using Newton Raphson Method for three equations and three unknowns?

Hi,I have a problem related to direct kinematic of stewart platform.I need to find unknown variables that i showed below.

my unknowns YA1,YA2,YA3...the other letters are known...

Thank u for your time in advance...

eq1='a^2+2*YA1*YA2-2*YA1(YP1+sqrt(3)*(XP2-XP1))-2*YA2*YP2-XP1^2-XP2^2+YP1^2+YP2^2+2*XP1*XP2-(h1^2+h2^2)+2*sqrt(3)*YP1*(XP2-XP1)+sqrt((h1^2-4*(YA1-YP1)^2)*(h2^2-4*(YA2-YP2)^2))=0'

eq2='a^2+2*YA1*YA3-2*YA3*(sqrt(3)*(XP2-XP3)-YP3)-2*YA2*YP2-XP2^2-XP3^2+YP3^2+YP2^2+2*XP2*XP3-(h2^2+h3^2)+2*sqrt(3)*YP3*(XP3-XP2)+sqrt((h2^2-4*(YA2-YP2)^2)*(h3^2-4*(YA3-YP3)^2))=0'

eq3='a^2-4*YA1*YA3+2*YA1*(sqrt(3)*(XP1-XP3)+3*YP3-YP1)+2*YA3*(sqrt(3)*(XP1-XP3)+3*YP1-YP3)-XP1^2-XP3^2+2*XP1*XP3+YP1^2+YP3^2-6*YP1*YP3+2*sqrt(3)*(YP1+YP3)*(XP3-XP1)-(h1^2+h3^2)+sqrt((h1^2-4*(YA1-YP1)^2)*(h3^2-4*(YA3-YP3)^2))=0'