A region G is formed from a 1 × 1 square by
removing a r × r square from one corner. (Here 0 < r < 1.)
• What is the largest square that fits entirely inside G ?
Justify your answer.
(The obvious choice is to fit a square of side (1 – r) into G.
But could some tilted square possibly have larger area? Explain.

NOTES: I know that the biggest square is (1-r)(1-r). However, how do you calculate the area of the tilted square?

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