Bell Work
1.
Given the following number line where XY = 7x + 2, XZ = 8x + 7
and YZ = 3x ­ 18: What is the value of XZ?
Notes 1F: Midpoint
If you know the coordinates of the endpoints of a segment, you can
calculate the coordinates of the midpoint by finding the average of the
x-coordinate and of the y-coordinate.
Midpoint Formula:
if A(x 1,y 1 ) and B(x 2 , y 2 ) are points on a coordinate
plane, then the midpoint of segment AB has coordinates
x1 + x 2
2
y 1 + y2
2
Example: Find the midpoint
1. (2, 4) and (-1, 7)
2. (-2, 3) and (5, -2)
Find the coordintes of the midpoint of a segment with the given endpoints.
1. A(0, 0) and B(4, 6)
2. C(2, 4) and D(0, -8)
5. A(-3, -2) and B(5, 4)
B(5,4)
3. E(-3, 2) and F(7, -6)
4. G(5, -6) and H(3, -3)
6. A(-2, 4) and B(4, 0)
A(-2,4)
B(4,0)
A(-3,-2)
Finding the coordinates of the endpoint of a segment.
The midpoint of KL is M(6, -2). One endpoint is K(4, 3). Find
the coordinates of the other endpoint.
Solution:
let (x, y) be the coordinates of L. Use the midpoint formula to write equations
involving x and y.
K(4, 3) L(x, y)
M(6, -2)
Find the coordinates of the other endpoint of the segment with the
given endpoint and midpoint M.
1. T(6, 2) M(2, 0)
2. A(-4, 3)
M(-1,-1)
Assignment
Assignment 1F
#1-17 ALL