H Geometry 4.3.notebook January 08, 2016

Do NowComplete the proof. Two circles intersect at two points. Prove that the segment joining the centers of the circles bisects the segment joining the points of intersection. (*Hint: This proof will take a detour)

Given: A; BProve: AB bisects CD

1.2.

3.

4.

5.

6.

7.

8.9.

1.2.

3.

4.

5.

6.

7.

8.9.

A; B Given

BA

C

D

A B

Reflexive Prop

BA

C

D

H Geometry 4.3.notebook January 08, 2016

Given the situation below (two angles that are both supplementary and congruent), what must the measure of each angle be?

H Geometry 4.3.notebook January 08, 2016

Theorem: If two angles are both supplementary and congruent, then they are right angles.

shorthand: If supp & = , then rt s~

*No longer have to write• That angles are supplementary (can now be assumed)• Headings "Statements" and "Reasons"

Example A

B CD

Given: AB = AC, BD = DCProve: AD is an altitude

~ ~

1.2.3.4.5.6.

1.2.3.4.5.6.

H Geometry 4.3.notebook January 08, 2016

ExampleGiven: O; B = CProve: AO BC

~ O

C

A

B

E

O; B = C~ 1.1.

2.2.3.3.

4.4.5.5.

6.6.7.8.9.10.11.

7.8.9.10.11.

Homework

4.3 p.182 #1, 2, 5 - 8, 11, 14