because there are 2 shapes in which have the same formula height times base so 6 is the base and n and m is both of the heights but they are the same height so you need to add them for the total height then mutiply the total height by 6 which means you can ALSO do 6n and 6m because if n=5 and m=2 6x5=30+6x2=12=42 and 6x(5+2)=42 and you can switch the equations around getting the same answer AND B is wrong because 6x5=30+2=32 NOT 42 and D is wrong because 6x5x2=60 not 42 SO it has to be A, C and E
