Two lines are parallel and there is a transverse line passing through both. There is an isosceles triangle as shown in the figure. angle x measurement is given as 8, and the problem is to find out angle y. Can anybody help please. I can only see a solution when angle abc is 90 degrees, but the question does not mention that. Is there any rule/theorem saying that it is 90 degrees? If not, how do I solve it.