Lesson 1-3

1

Lesson 1-3

Use Midpoint and Distance Formula

Warm Up

2

1.Find a point between A(-3,5) and B(7,5).

2.Find the average of -11 and 5.3.Solve4.Find 30 to the nearest

hundredth.5.Find 5 +20 to the nearest

hundredth.

52

7

x

3

Midpoint

A point that divides a segment into two congruent segments

Definition:

-5 5

SRQPOLKJIHG N

4

Midpoint on Number Line - Example

Find the coordinate of the midpoint of the segment PK.

a b 3 ( 2) 10.5

2 2 2

Now find the midpoint on the number line.

0

M

5

Segment BisectorAny segment, line or plane that divides a segment into two congruent parts is called segment bisector.

Definition:

B

E

D

FA

BE

D

FA

E

D

A F

B

AB bisects DF. AB bisects DF.

AB bisects DF.Plane M bisects DF.

Practice

6

Identify the segment bisector of PQ . Then find PQ.

1.

343ANSWER MN;

Practice

7

Identify the segment bisector of PQ . Then find PQ.

2.

line l ; 11 57

ANSWER

Homework #3

8

p. 870: 13-20p. 19: 1-16, 48, 55, 56, 60-64

If A(x1,y1) and B(x2,y2) are points in a coordinate plane, then the midpoint M of AB has coordinates

9

Midpoint Formula

The coordinates of the midpoint of a segment are the averages of the x-coordinates and of the y coordinates of the endpoints.

1 2 1 2,2 2

x x y y

Practice

10

The endpoints of AB are A(1, 2) and B(7, 8). Find the coordinates of the midpoint M.

ANSWER (4,5)

ANSWER (– 6, – 8)

The midpoint of VW is M(– 1, – 2). One endpoint is W(4, 4). Find the coordinates of endpoint V.

If A(x1,y1) and B(x2,y2) are points in a coordinate plane, then the distance between A and B is

11

Distance Formula

Lesson 1-2: Segments and Rays 12

Practice

13

Homework #4

14

P. 19: 17-27, 31-37, 41, 42, 49-52