Two factors of 30 add up to 9. what are they?

factors of 30 are numbers by which 30 is divisible.
if we list out 30 as a product of factors 30 = 1 x 30
30 = 2 x 15
30 = 3 x 10
30 = 5 x 6
therefore all the factors of 30 are - 1,2,3,5,6,10,15,30
the numbers 3 and 6 add up to 9.
therefore the 2 factors that add up to 9 are 3 and 6

The length of what is left would be 1 1/2 feet long.