what is the new rule announced to the tributes? how does katniss respond and what does this show about character?

The new rule was that the last two survivors of the same district will be declared the winner. Katniss, after hearing the new rule, calls the name of Peeta. This act of Katniss reveals that she cares for Peeta.

Explanation:

The Hunger Games is a novel written by Suzanne Collins. In the novel, in Chapter 18, the new rule that was announced to the tributes was that the last two survivors of the same district will be declared winners.

After hearing to this new rule, Katniss calls the name of Peeta. She called the name of Peeta because she realized that Peeta and she both could survive the game. This reveals that Katniss cared for Peeta otherwise she would not have taken such a risk of calling his name when she tends to remain hidden. She even forgot about herself and thought of Peeta first.