Ariom 4 says that given a point p₁ and a line 1₁, there is a unique fold perpendicular to l₁ that passes through point p₁. Let l₁ be the line that passes through points (1,6) and (3,3). Apply Axiom 4 to find the equation to the fold that is perpendicular to l₁ and passes through p1 = (3,5).

Fig: 1