Hey there sorry if this is in the wrong thread, but I need some help with this problem I'm stuck on.

Give a point (a,b) with 0 < b < a

determine the minimum perimeter of a triangle with one vertex at (a,b), on the x-axis,

and one on the line y = x.

I hope someone can help/guide me through this problem, so I can understand how to do this problem thanks.