If the coordinate of A is x, and that of the midpoint of AB, M, is m then
the distance AM is m-x so the distance AB = 2*(m-x)
So the coordinate of B is x + 2*(m-x) = 2m-x
For coordinates in more than one dimension, apply the above rule separately for each dimension.
A+ = segment C A
double the length
No. The midpoint of a line segment is the single point exactly halfway between each endpoint.
Use the midpoint formula.( x1 + x2 / 2 , y1 + y2 / 2 )For example, if you were given segment QR with midpoint M(-1, -1) and endpoint Q(-8, 10):(-1, -1) = ( x1 + -8 / 2 , y1 + 3 / 2)X COORDINATE--------------------1 = x1 + -8 / 2-2 = x1 - 86 = xY COORDINATE--------------------1 = y1 + 10 / 2-2 = y1 + 10-12 = y
The other end point is (8,-10).
If you are only given one endpoint and a midpoint, you know what the middle of the line segment is. Since the midpoint is half of what the line segment's length is, all you have to do is find the distance between the endpoint given and the midpoint, then add that coordinate to your midpoint and get your other endpoint. For example: Endpoint A: (4,5) Midpoint: (6,8) Distance between: (2,3) Add (2,3) to (6,8) and get Endpoint B: (8,11).
Each coordinate of the midpoint of a straight line segment is the arithmetic mean of the coordinates of the endpoints. So the y-coordinate is (0+15)/2 = 7.5
The 'x' coordinate of the midpoint is the average of the 'x' coordinates of the segment's ends. The 'y' coordinate of the midpoint is the average of the 'y' coordinates of the segment's ends.
If you mean endpoint (6, 9) and midpoint (7, 6) then the other endpoint is (8, 3)
If you mean endpoints of (0, 0) and (0, 15) then the midpoint is at (0, 7.5)
The direction of missing endpoint is the same as the direction from the known end point to the midpoint. The distance from the midpoint to the missing endpoint is the same as the distance from the known end point to the midpoint. In coordinate geometry it is simple. If the known end point is (p, q) and the mid point is (r, s) then the missing point is (2r - p, 2s - q).
4
A line segment has endpoints and a midpoint.
-- Find the distance between the endpoint and the midpoint.-- Double that distance to get the length of the complete segment.-- When you're finished, sit quietly for a moment and ponder the meaning of "midpoint".
A+ = segment C A
-2.5
double the length