Answer :
Part 1 is 16cm and Part 2 is 4cm
4 x 4 = 16 this makes part 2 four times as long as part 1
16 + 4 = 20 this makes the whole line segment
4 x 4 = 16 this makes part 2 four times as long as part 1
16 + 4 = 20 this makes the whole line segment