Informal Geometry

1
Informal Geometry

• Goal Bisect a segment and find its coordinates

2
Patty Paper Activity

• Using a straight edge draw AB
• Fold paper so A is on top of B
• Label the point where the fold intersects AB as M
• Measure AM, MB, and AB.
• What do you notice?

3
Vocabulary

• Midpoint point that divides a segment in two
  even parts
• Segment Bisector a line that intersects a
  segment at the midpoint
• Bisect divide into 2 congruent parts

4
Examples

• Find AM and MB
• Find PS and RS

5
A bit of a challenge?

• Find x

6
Midpoint Formula

• Midpoint average x and average y
• Formula

7
Example

• Find the midpoint of AB
• A(1, 2) and B(7, 4)
• A(-2,3) and B(5,-1)

8
Homework

• 56 (11-14, 16-34 even, 43)