Area total de um banheiro          

PISO                                 Parede da frente e do fundo             Paredes laterais
Aq=b.h=2m.3m=6m                Aq=b.h=3m.1,15m=3,45           Ar=b.h=2m.1,15=3,15

                                                   3,45+3,45=6,90                          3,15+3,15=6,30

Area total
6m+6,90+6,30=19,20