so assumn that the measures given are the legnths of the sides perimiter=side1+side2+side3 so side1=4 and 1/2 side2=5 and 1/2 side3=6 subsitute p=(4+1/2)+(5+1/2)+(6) associative prpoerty says (a+b)+c=a+(b+c) (it deals with addiont with parenthasees) p=4+1/2+5+1/2+6 p=4+5+1/2+1/2+6 p=9+1+6 p=10+6 p=16 inches