RE: how to calculate arctan from the resultf from 'solve' command

restart; with(plots):

R_circ := 455.0353986;

Is6 := 716.6183759;

Imu6 := 101.1189775;

sys := { (x - R_circ - Imu6)^2 + y^2 = R_circ^2 , x^2 + y^2 = Is6^2 } ;

solve( sys, {x,y} );

answer5 := %;

answer5[1];

arctan((answer5[1][2] / answer5[1][1]));

Error, invalid input: arctan expects its 1st argument, y, to be of type algebraic, but received y/x = .8219198646