# Thread: coordinates that trisect a line segment

1. ## coordinates that trisect a line segment

this question I don't have much work to show. :

IF A is (3,6,8) and B is (6,0,-1). Find the points that trisect the line segment.

I thought I would do A+B(1/3) and A+B(2/3) didn't work correctly though. the correct answer is (4,4,5) and (5,2,2).

Thanks in advance

2. Originally Posted by colorado
this question I don't have much work to show. :

IF A is (3,6,8) and B is (6,0,-1). Find the points that trisect the line segment.

I thought I would do A+B(1/3) and A+B(2/3) didn't work correctly though. the correct answer is (4,4,5) and (5,2,2).

Thanks in advance
note the distance between the x-coordinates is 3 ... so, the x-coordinates for the other two points have to trisect this component length of 3. 3/3 = 1 ... the x-coordinates must be 4 and 5.

do the same for the y and z coordinates.

y-coordinates will be 6/3 = 2 units apart

z-coordinates will be 9/3 = 3 units apart

3. Originally Posted by colorado
I thought I would do A+B(1/3) and A+B(2/3)
Right idea, but not accurate. You should have gone for A + (1/3)(B–A) and A + (2/3)(B–A).