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## 'Trominoes' printed from http://nrich.maths.org/

A tromino is a $3 \times 1$ block:

What sized rectangles may be made using trominoes? You can print
off and cut out trominoes from this

sheet . Alternatively, if you
have a set of the game Jenga, then use the blocks as trominoes (but
check they are $3 \times 1$ first)

Can you cover $63$ squares of an $8\times 8$ chessboard using
trominoes? (Why can't you cover $64$?). If so, which square remains
uncovered, and are there other arrangements of the trominoes which
would lead to a different square being left uncovered?

Think of some other squares which cannot be covered with trominoes.
Can you "almost" cover them, leaving only one hole? When can an $n
\times n$ square be covered or "almost" covered?