Answer:
1. No, Student 1 did not make any errors. However, their use of a ruler, or lack of thereof, could result in a lack of accuracy.
2. The student manually found the points and connected them together, doing so for both A and B and thus finding the intersection.
3. Since there is no formula used, the result may not be accurate. The student can only guess the position of the intersection, not know exactly (i.e. when the points are positioned at decimal numbers.)