The distance from three points ABC not on the same straight line to plane a is equal, and a does not belong to a 1. At least one edge of triangle ABC is parallel to a 2. At most two sides of triangle ABC are parallel to a 3. Only one edge of triangle ABC intersects with a What are the correct ones?

The distance from three points ABC not on the same straight line to plane a is equal, and a does not belong to a 1. At least one edge of triangle ABC is parallel to a 2. At most two sides of triangle ABC are parallel to a 3. Only one edge of triangle ABC intersects with a What are the correct ones?

If three points ABC are on the same side of plane a,
Then all three sides are parallel to plane a,
At this time, all three sides do not intersect plane a;
If there are two points on one side of plane a,
The other point is on the other side of plane a,
One side is parallel to plane a,
The other two sides intersect plane a
So only one, right