EDGE Math 8

Identify the missing statements or justifications that will complete the two-column proof. Type the letter of your answer in each blank.

Given:	$ND > NI$ M is the midpoint of $\bar{ID} .$
Prove:	$ΔNMD$ is an obtuse angle.

Choices:

f.	Definition of obtuse angle
g.	$∠ NMD$ and $∠ NMI$
h.	M is the midpoint of $\bar{ID} .$
i.	$m ∠ NMD + m ∠ NMI = 180 °$
j.	Reflexive Property of Segment Congruence

Proof:

Statements

Reasons

ND > NI

1. Given

2. Definition of midpoint

\bar{NM} ≅ \bar{NM}

m ∠ NMD > m ∠ NMI

form a linear pair.

5. Definition of linear pair

6. Linear Pair Postulate

m ∠ NMD + m ∠ NMD

> 180 °

Statements 4 and 6, and

8. Addition Property of Inequality

9. Multiplication Property of Inequality

10.

ΔNMD

is an obtuse angle.

10.

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