A Strange Wild Song (Poem by Lewis Carroll) Written circa 1870
A preparatory problem for the Kangaroo contest gave me a lot of trouble. I got it from Practice Materials, for Grade 11 and Grade 12. It's the first problem on the list, so it's rated as simple. And yet... not too simple.
To avoid bothering myself with all sorts of topological juggling, I decided to try a solution with my own hand. I cut out the figure and tried to fit them together, finally obtaining the Answer: Option A is correct.
Below are the photos that demonstrate this. It remains to be seen how a less...manufactured solution would have been possible.
I cropped the figure and arranged option A so that it would fit into the coverage by translation.
And here is the result
The other cases do not give the correct answer.
Option B
Option C
Option D
Option E
And this is what the 5 response options look like when returning by translation after the matching attempt.
A coloring of the pentagons as they fit, to give us a more intuitive picture
