This is one of the simplest problems in the series if white knows where to start.
We've seen very similar patterns while studying Shape 23 and 24. Just to repeat here to make the series complete.
Can the external liberty make any difference?
Can secure this corner?
The extra external liberty makes a lot of difference. What's the best strategy for white?
Let's study this 'incomplete' Carpenter's Square.
We already learned that attacking at 'a' from outside is not working. What else?
secure this corner?
