What is the locus of all points in a plane equidistant from two given lines in the plane?

Question

1. A line parallel to both lines and halfway between the lines

2. A line segment connecting the two lines

3. A curved shape thats passed between two lines

4. A circle with one point on each line

Answer 1

first, find one point that meets the conditions, and then try to visualize (make a drawing!) others.