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Home > GC > Chapter 9 > Lesson 9.2.2 > Problem 9-71

9-71.

Given the information in the diagram at right, prove that . Write your proof using any format studied so far.  

Rectangle A, B, C, D where side D, C, is missing. Instead diagonals D, B and A, C, are drawn.

Proof # 1

	
Proof Bubble #1: Given: Line D, A is equal to line C, B.

Proof bubble #2: Given: Angle D, A, B, is equal to angle C, B, A.

Proof bubble #3: reflexive property: Line A, B is equal to line B, A.

	
Proof bubbles # 1, # 2, and # 3 each have an arrow pointing down to proof bubble # 4. Proof bubble # 4: Triangle D, A, B, is equal to triangle C, B, A. Outside of bubble # 4 is the statement S, A, S, congruency.

	
Proof bubble # 4 has an arrow pointing down to bubble # 5. Proof bubble # 5: Angle C is congruent to angle D. Outside of bubble # 5 is the statement All triangles have equal parts.

Proof # 2

Proof # 3

Proof # 4

Proof # 5