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
