我有1 條F.1 Maths 唔知點做.可不可以解釋一下&做比我睇.

1)
(a)A string 80 cm long is used to form a square,find the length of a side of the square.
(b)If the string is cut into two parts.Each part is used to form a square.It is given that the length of a side of a square is 4 times the other.Find the length of a side of the larger square.
(c)The larger square obtained in (b) is then transformed to a rectangle.The length of the rectangle is larger than twice the width by 2 cm.Find the area of the rectangle.

我一定要解釋.教我做.拜托.........