The steps to construct a circle circumscribing a triangle are:
- Construct a perpendicular bisector of one side of the triangle
- Construct another perpendicular bisector of another side of the triangle
- The point of intersection of these two perpendicular bisectors is the center
of the circle, we are about to construct.
- Adjust the width of the compass between the intersection point to any of
the corners of the triangle. This width should be the same for all three
vertices
- With the pointer of the compass is located at the intersection point, construct the circle
What could possibly go wrong when the circle only passes two vertices, is the width of the compasses has changed while constructing the circle
Answer: First option