Two bars are used to support a load $P.$ When unloaded, $AB$ is $125$ mm long, $AC$ is $200$ mm long, and the ring at A has coordinates $(0,0).$ If a load is applied to the ring at $A,$ so that it moves to the coordinate position $(6\mathrm{.}25mm,-18\mathrm{.}25mm),$ determine the normal strain in each bar.