21. Which property of equality justifies the following statement? If \( m \angle 1 = 85 ^ { \circ } \) and \( m \angle 4 = 85 ^ { \circ } \) , then \( m \angle 1 = m \angle 4 \) .
A. addition
B. reflexive
C. symmetric
D. substitution
Pregunta
Answer
D. substitution
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