Lesson 9 · Module 4 Final Project — Knowledge ChecksAnswer key

Why is the line manhattan.position = navigator.position necessary each leg?

1. A.It resets the robot to (0,0)
2. B.So the next compute_path() starts from where the robot actually is now, not the original start✓
3. C.It updates the heading
4. D.It is not necessary

Manhattan doesn't automatically know the robot moved. Without updating its position, every leg after the first would compute a path from (0,0) — the wrong starting point.

At the start of leg 2, what is the Navigator's heading?

1. A.Always reset to 0 (North)
2. B.Whatever heading it ended leg 1 with✓
3. C.Always 2 (South)
4. D.Random

The Navigator keeps its state. It begins each leg facing however it finished the last — which is exactly why turn_to() must work from the real current heading.

On the second leg the robot drives a clearly wrong path. What's the first thing to check?

1. A.The battery voltage
2. B.Whether manhattan.position was updated after leg 1✓
3. C.The color of the grid lines
4. D.The HEADING_NAMES list

A wrong path on leg 2+ almost always means the position update was skipped, so compute_path started from (0,0) instead of where the robot really is. Check that line first.

You want the robot to end where it began. What's the simplest change?

1. A.Create a new Navigator facing North at the end
2. B.Add (0, 0) as the final destination in the list✓
3. C.Reverse the LineTrack motors
4. D.Restart the program

The loop already computes and drives a path to each destination. Just append home (0,0) to the list and the last leg drives the robot back.