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HW-Worksheets
Quiz TUESDAY
www.westex.org HS, Teacher Websites
5-9-12
Warm up—ALG 2 CPA
1. Rewrite the radical 2. What is the average
expressions in simplest
of 17 and 41?
radical form.
a)
80
b)
54
3. The average of 25 and
c) 3 150
another number is 39.5.
What is the other number?
Today’s Goal:
I will be able to:
1. find the midpoint given both endpoints of a
segment.
2. find the endpoint of a segment given 1 endpoint
and the midpoint of the segment.
3. find the length of a segment given both
endpoints.
4. find the distance between two points in the
coordinate system.
HW-Worksheets
Quiz TUESDAY
www.westex.org
HS, Teacher Websites
Name ______________________
Date _______
ALG 2 CPA
Midpoint & Distance Formula
Today’s Goal:
I will be able to:
1. find the midpoint given both endpoints of a segment.
2. find the endpoint of a segment given 1 endpoint and the midpoint of the segment.
3. find the length of a segment given both endpoints.
4. find the distance between two points in the coordinate system.
Sometimes you need to find the point that is exactly between two other points. This middle
point is called the ___________________.
If you are given two numbers, you can find the number exactly halfway between them by
__________ them (adding them together & dividing by two). For example, the number exactly
5  10  = 15 = 7.5.
halfway between 5 and 10 is
2
2
The Midpoint Formula works exactly the same way. If you need to find the point that is
exactly halfway between two given points, just ___________________ the
___________________ and the _________________.
Midpoint Formula
Finding the Coordinates of a Midpoint
Ex 1
Find the coordinates of the midpoint of CD with endpoints C (-2, -1) and D (4, 2).
YOU TRY:
Find the coordinates of the midpoint of EF with endpoints E (3, -5) and F (-9, 13).
Finding the Coordinates of an Endpoint
Ex 2
M is the midpoint of AB . A has coordinates (2, 7) and M has coordinates (6, 1). Find the
coordinates of B.
Step 1 Let the coordinates of B equal ________.
Step 2 Use (plug into) the Midpoint Formula
Step 3 Find the x-coordinate.
Find the y-coordinate.
YOU TRY:
S is the midpoint of RT . R has coordinates (-6, -1) and S has coordinates (-1, 1). Find the
coordinates of T.
The ____________________ can be used to find the distance d between two points in a
coordinate plane.
Ex 1
Use the distance formula to find the distance
between points A and B. Express your answer in
simplified radical form.
Ex 2
Use the Distance Formula to find the length of the segment.
QR with endpoints Q(2, 4) and R(-3, 9).
YOU TRY:
Use the Distance Formula to find the length of each segment or the distance between
each pair of points.
1. EF with endpoints E(-8, 1) and F(1, 1).
2. T(8, -3) and U(5, 5)
3. N(4, -2) and P(-7, 1)