Geometry: An Interactive Journey to Mastery

Lesson 13: A Return to Parallelism

2. M, N, and O are midpoints of the sides of +ABC.
   ͼ௘6HHFigure 13.10௘ͽ
   D௘ͽ ,IBC = 20, then MO =?
   E௘ͽ ,IMN = 13, then AC =?
   F௘ͽ ,VNO AB&?
   G௘ͽ ([SODLQZK\‘B is congruent to ‘MON.


3. Consider the triangle with vertices A ͼ௘௘ͽB ͼ௘í௘ͽDQGC ͼ௘௘ͽ
   D௘ͽ )LQGWKHPLGSRLQWM of AB.
   E௘ͽ )LQGWKHPLGSRLQWN of AC.
   F௘ͽ 9HULI\WKDWMN is parallel to BC.


4. In the diagram in Figure 13.11, B, D, F, and H bisect the line
   segments on which they lie.
   D௘ͽ ,ICG = 20, what are the values of HB and FD?
   E௘ͽ ,VHB FD&?


5. The line segment inside the triangle in Figure 13.12 connects
   midpoints. Find the values of x, y, and z.

A

N

O C

B

M

Figure 13.10

Figure 13.11

A

D

C

E

B

H

G

F

ͼyíͽ

x + 4^10 x + 1

4 yí

51°

z

Figure 13.12