What face has one curved face 2 flat faces?

Answer 1

When you say "What face" did you mean "What solid" has one curved face and two other flat faces?

A solid that can be imagined is a melon wedge, cut from a sphere. Two flat faces come from the two cuts with a knife, and the one curved face that formed the rind.

If you did not mean "What solid" then that makes your question unclear. I cannot imagine a face made from three other faces. Perhaps a face made from three other lines with one of them curved? It would seem you used a word wrong somewhere in your original question.