Mid point is the point which divides a line segment into two equal halves. In general it is the average of x values and y values.
If (x1, y1) and (x2, y2) are the end points of a line segment then the mid point is given by the formula ((x1+x2) /2, (y1 + y2) /2).
Example 1: Find the mid point of A (-1, 9) and B (7, -25)
Here (x1, y1) = (-1, 9) and (x2, y2) = (7, - 25)
x1 = -1, x2 = 7, y1 = 9, y2 = -25
Mid point = ((x1 + x2) /2 , (y1+ y2) /2)
Mid point = ( (-1+7) / 2, (9 – 25)/2)
Mid point = (6/2, -16/2)
Mid point = (3, -8)
Hence the mid point of the given line segment AB is (3, -8)
Example 2: The mid point of a line segment is (7, 3). One end of a line segment is (4, 8). Find the other end.
Here x1 = 4 and y1 = 8 and mid point = (7, 3)
Mid point = ((x1 + x2) /2 , (y1 + y2) / 2)
(7, 3) = ((4 + x2) / 2, (8 + y2 )/ 2)
7 = (4 + x2) /2 3 = (8 + y2) / 2
Multiply with 2 on both sides Multiply with 2 on both sides
14 = 4 + x2 6 = 8 + y2
Add – 4 on both sides Add -8 on both sides
10 = x2 -2 = y2
Hence the other end of the line segment = (x2, y2) = (10, -2)