Question 9(Multiple Choice Worth 6 points)

(05.01 LC)

The figure below shows triangle NRM with r2 = m2 + n2:

Triangle NRM has legs m and n, and r is the length of its longest side.

Ben constructed a right triangle EFD with legs m and n, as shown below:

Triangle EFD has legs m and n and hypotenuse f.

He made the following table to prove that triangle NRM is a right triangle:


Statement Reason
1. r2 = m2 + n2 Given
2. f2 = m2 + n2 Pythagorean Theorem
3. f2 = r2 Substitution
4. f = r Square Root Property of Equality
5. Triangle NRM is congruent to triangle EFD SSS Postulate
6. Angle NRM is a right angle ?
7. Triangle NRM is a right triangle Angle NRM is a right angle

Which reason best fits statement 6?
Triangle Proportionality Theorem
All sides of both the triangles are equal
Corresponding parts of congruent triangles are congruent
Triangle EFD has two angles which measure less than 90°