Hello!
Since (1, -2) is the point of intersection, then it is the solution to the system of equations. Let's test our answer to see if it's correct:

But that's only for the first one, let's test for the second one:

This is how we know that (1, -2) is the solution to the system of equations. Hope I helped! :3
You haven't included a diagram, however, if it's an isosceles triangle 2 of its sides will be the same and 1 will be different