1 x 4

4 x 1

(a)  

2 x 4

4 x 2

(a)  

3 x 4

4 x 3

(a)  

4 x 4

(a)  

4 x 5

5 x 4

(a)  

6 x 4

4 x 6

(a)  

7 x 4

4 x 7

(a)  

8 x 4

4 x 8

(a)  

9 x 4

4 x 9

(a)  

10 x 4

4 x 10

(a)