A man stands at a point X on the bank of a river and looks at the top of a tower which is situated exactly opposite to him on the other bank. The angle of elevations is `45^@`. The man then walk 300 m at right angle to the bank and away from it, to the point Y. From Y he looks at the top of the lower and finds the angle of elevations as `30^@`. Calculate the height of the tower and the width of the river.