Answer
Ans a) Angle XBC = 55 degree because corresponding angles in parallel lines are equal
Ans b) Angle XBC = Angle XCB ( Given )
Let the angle BXC be x
55 + 55 + x = 180 ( Angle sum property of a triangle
110 + x = 180
x = 180 - 110
x = 70
Hope you got the answer to the question