1. Refresher…  ABC is isosceles Line CD bisects  C and is a perpendicular bisector to AB If m  A is 50, find m  B, m  ACD, and m  ACB *After notes are done, you will be allowed to do quiz and test corrections in class.*

2. Midsegments of Triangles Geometry Mrs. King and Ms. Reed Unit 4, Day 4

3. Definition Midpoint – The point that divides the segment into two congruent segments. ABM

4. Definition Midsegment of a Triangle – a segment connecting the midpoints of two of its sides. A B C MN

5. Draw a Midsegment: In your notes, draw  ABC. Find the midpoint of AC and call it point M. Find the Midpoint of BC and call it point N. Measure MN and AB. What do you notice?

6. Midsegment M is a midpoint of AB N is a midpoint of BC MN is a midsegment of  ABC A B C MN

7. Triangle Midsegment Theorem If a segment joins the midpoints of a triangle, then the segment is parallel to the third side of the triangle and half its length

8. How it is used: Find x: A B C MN x 16

9. How it is used: LM is a midsegment of  ABC If AL = 4, what does AB = ? If LM = 5, what does AC = ? If BC = 18, what does CM = ? AB = 8 AC = 10 CM = 9 A B C LM

10. Practice In quadrilateral EFGH, the points A, B, C, and D are midpoints and EG = 18 cm. Find AB and CD. Is AB || CD? Justify your answer. Draw in segment FH. If FH = 25, Find BC and AD.

11. Homework Work Packets: Midsements of Triangles