Should be 1/11.Gradient of AB = 11

How can this be if both B and C are on y = 2?Midpoint of BC = (-0.5, 0.5)

Should be 0.Gradient of BC = -0.5

I would recommend considering BC and AC. The first segment is horizontal, so the equation of the perpendicular is x = 1. The second segment's gradient is -1, which also makes the perpendicular's equation rather simple.