Like this presentation? Why not share!

# 1-6 the coordinate plane part 2

## by jcirulli on Sep 28, 2010

• 704 views

Prentice Hall Geometry

Prentice Hall Geometry

### Views

Total Views
704
Views on SlideShare
704
Embed Views
0

Likes
0
6
0

No embeds

### Categories

Uploaded via SlideShare as Microsoft PowerPoint

## 1-6 the coordinate plane part 2Presentation Transcript

• 1-6 The Coordinate Plane part 2
L.E.Q. How do you find the coordinates of the midpoint of a segment in the coordinate plane?
• Midpoint
On a number line
formula:
• On a coordinate plane formula:
Where is the x coordinate of the midpoint and is the y coordinate of the midpoint.
• y
10
10
9
8
7
x = 1
x = 9
6
A(1, 7)
y = 7
y = 3
5
y
4
3
B(9, 3)
2
C(5, 5)
x
1
x
0
-1
-2
-2
10
-1
2
4
6
8
10
-2
3
7
1
9
-2
5
0
Midpoints
Find the midpoint, C(x, y), of a segment on the coordinate plane.
• QS has endpoints Q(3, 5) and S(7, -9). Find the coordinates of its midpoint M.
EXAMPLE: Finding the midpoint.
• Use the example to model your solution for this problem.
• y
10
10
9
Finding an Endpoint
8
Suppose C(3, 5) is the midpoint of AB. Find the coordinate of B.
7
B(-1, 8)
6
5
4
3
A(7, 2)
2
C(3, 5)
1
x
0
-1
-2
-2
10
-1
2
4
6
8
10
-2
3
7
1
9
-2
5
0
x-coordinate of B
y-coordinate of B
Replace x1with 7and y1with 2
B(x, y) is somewhere over there.
midpoint
Multiply each
side by 2
Add or subtract toisolate the variable
• EXAMPLE: Finding an Endpoint.
The midpoint of AB is M(3, 4). One endpoint is A(-3, -2). Find the coordinates of the other endpoint B.
• The midpoint of DG is M(-1, 5). One endpoint is D(1, 4). Find the coordinates of the other endpoint G.