[Post activity discussion]
Some of you enquired the "complete" set of solution (after the class discussion) - i.e. the various possibilities that arise from various assumptions.
Here are the possibilities and assumptions that we need to be clear before solving the problem:
In scenario 2, some of you suggested using nets (something you learnt in primary school).
Here, it's good to draw the net and write the dimensions clearly to ensure the correct numbers are used for calculation.
Look, there are 2 possible 'nets' that could give the shortest path.
Do NOT assume the 2 nets give the same "diagonal" length.
[Do not apply "seeing is believing"]
Always compute the numbers to check.
The 3rd scenario was the one that we spent a significant amount of time to discuss in class - Refer to the "Romeo & Juliet" box that I brought to the class to help you visualise better.
Here, you would have to apply Pythagoras Theorem twice.