Geometry Intro to Proofs

Given: <1 and <2 are a linear pair. Conclusion: m<1 + m<2 = 180. What is the reason that allows you to draw that conclusion?

• Angle addition postulate

• Definition of straight angle

• Linear Pair Postulate

• Definition of supplementary

Given: AB is the segment bisector of PQ. What conclusion can you draw?

• PF = QF

• F is the midpoint of PQ

• m<PFA = m<QFA

• <PFQ is a straight angle

Which of the following conclusions CANNOT be drawn just by looking at the diagram?

• GH and AB intersect at D

• <GDA and <HDB are vertical angles

• D is the midpoint of GH

• G, D, and H are collinear

Which of the following CAN you conclude from the diagram?

• lines l and m are perpendicular

• <a and <b are adjacent

• <a and <b are complementary

• m<a = m<b

Given: PL is the angle bisector of <RPQ
What can you conclude by definition of angle bisector?

• m<RPL = m<LPQ

• <RPL + m<LPQ = m<RPQ

• <RPQ is acute

• m<RPQ = 90

What is the justification?

• Symmetric Prop.

• Angle addition postulate

• Reflexive Prop

• Transitive Prop.

In the given proof, what is the statement for step 2?

Why are these 2 triangles congruent according to your proof?

• ASA

• SAS

• SSS

• Cannot be determined

In the given proof, what is the statement for step 4?

Given: ∠1 and ∠3 are vertical angles. What should you conclude by the vertical angles theorem?

•  $\angle1$  and $\angle3$  are right angles.