Suppose we have to cover the xy plane with identical tiles such that no two tiles overlap and no gap is left between the tiles. Suppose that we can chose the tiles of the following shapes: equilateral triangle, square, regular pentagon, regular hexagon. Then the tilings can be done with the tiles of
A) all four shapes
B) exactly three of the four shapes
C) exactly two of the four shapes
D) exactly one of the four shapes
I am not able to comprehend the question please help….