GH GH\,GH and IJ IJ\,IJ are parallel lines. ABC ABC\,ABC is an isosceles triangle where A A\,A and B B\,B lie on the line GHGHGH, and C C\,C lies on the line IJIJIJ. Angle XAC=130∘XAC = 130^\circXAC=130∘ where X X\,X is a point on the line GHGHGH.
Find the size of angle BCJBCJBCJ.
Give a reason for each stage of your working.