A rectangular billboard in space has the dimensions 10 m 20 m. How fast, and in what direction with respect to the billboard, would a space traveller have to pass for the billboard to appear square?

a)The space traveller would have to travel at 0.5c in a direction parallel to the shorter side of the board.

b)The space traveller would have to travel at 0.87c in a direction parallel to the shorter side of the board.

c)The space traveller would have to travel at 0.5c in a direction parallel to the longer side of the board.

d)The space traveller would have to travel at 0.87c in a direction parallel to the longer side of the board.

e)The space traveller would have to travel at 0.5c in any direction.