6 x 6

(a)  

7 x 7

(a)  

7 x 8

(a)  

8 x 9

(a)  

8 x 3

(a)  

8 x 5

(a)  

6 x 4

(a)  

6 x 7

(a)  

9 x 9

(a)  

4 x 9

(a)  

4 x 8

(a)