To find data size on selected columns

Database

To find data size on selected columns

Hi,

Can someone with query to find size of selected rows in columns from teradata table. For ex

A   B   C    D   E

1   1    1   1    1

2   2    2   2    2

1   3    1    1   1

1   4    1     1   1

Need size for A + B for where A = 1

Thanks in Advance