Download 3/10 Geometry Bell Ringer

3/10 Geometry Bell Ringer
What’s the distance between (1, 4)
and (8,28). Simplify your answer!
Homework: Due
TOMORROW!!!!
Pg. 37 (#1 – 7)
Pg. 504 (#1 – 6)
Pg. 492 (#1 – 6) Bonus (79)
What’s the midpoint
between -3 and 5?
3/10 News and Notes
• Perfection: 4th Period
• Missing Quizzes:
6
5
4
3
2
1
0
– 1st: Brian
– 7th: Kaneisha, Leslie
– 8th: Desirae, Diego, Jasmine Z
Perfection Competition Daily Results
6
5
5
4.5
4
1st
2nd
4th
7th
8th
• HW Due TOMORROW again.
• Unit Test next Tuesday!
• Tutoring session today after school in Room 218!!!
Today’s Goal
• Review Distance Formula and learn Midpoint
Formula.
Homework: Due
TOMORROW!!!!
What does midpoint mean?
•
•
•
•
Splits something in half
Right in between two points
Directly in the middle
The average of two points
Homework: Due
TOMORROW!!!!
What’s the average of -3 and 5?
• Add them, then
divide by the
number of terms:
Homework: Due
TOMORROW!!!!
35
2
2
 1
2
Today is just as easy as finding the
average of 2 numbers!
• Find the average of the x-values
• Find the average of the y-values
• Represent answer as (x,y)
Homework: Due
TOMORROW!!!!
Example #1 – Finding midpoint in the
coordinate plane
• Find the midpoint of the line between (3,2) and (7,4).
• Step 1: Plot Points & Connect Line
• Step 2: Find average of x values:
x1  x2 3  7

2
2
•
10

5
2
Step 3: Find average of y values:
y1  y2 2  4
6

 3
2
2
2
• Step 3: Put it together:
 3  7 2  4   10 6 
,

   ,  = (5,3)
2   2 2
 2
(7,4)
(3,2)
Quickly
• (3,2) and (7,4)
• What’s half way
between 3 and 7?
5
• What’s half way
between 2 and 4?
3
• So, (5,3)
Quickly Fill in Vocab, then move to
Example 2 on your own
Midpoint
Formula
Homework: Due
TOMORROW!!!!
point directly in
the middle of two x  x y  y
 1 2 1
2 
,


points.
2 
 2
Example #2
• Find the midpoint of the line between
(-5, 1) and (3, 5).
 x1  x2 y1  y2 
,


2
2


  5  3 1 5    2 6 
,
, 


2   2 2
 2
= (-1, 3)
Homework: Due
TOMORROW!!!!
(3,5)
(-5,1)
Now flip it for Example
Homework:
3: Due
TOMORROW!!!!
• Line segment AB has an endpoint of A (1,2)
and midpoint (3, 5). What are the
coordinates of point B?
2  y2
1  x2
5
3
2
2
2  y2
1  x2
* 2  5* 2
* 2  3* 2
2
2
2  y2  10
1  x2  6
y2  8
x2  5
B  (5,3)
Exit Ticket
• Find the midpoint of the line segment
between the two points shown.
•
•
•
•
A.
B.
C.
D.
1 
 ,0 
2 
 1 
  ,0 
 2 
 1
 0, 
 2
1

 0, 
2

Homework: Due
TOMORROW!!!!