5. There are 20 cards labeled with digits $1-20$. Now, the card labeled “1” is recorded as $1 \mathrm{~cm}^{2}$, the card labeled “2” is recorded as $2 \mathrm{~cm}^{2}, \cdots$ to represent the area of the card.
(1) When one card is randomly drawn from these 20 cards, try to find: the probability that the area of the drawn card equals the area of a square with the side length being the digit on the card;
(2) When two cards are randomly drawn from these 20 cards, try to find: the number of ways in which the sum of the digits on the two drawn cards exactly equals the area of a square with the side length being the digit on one of the cards.
5. (1) $\frac{1}{5} ;$ (2) 22 kinds.