Answer:
Option C is correct.
Step-by-step explanation:
Given a proof of Angle Sum property of triangle.
We have to find the missing reason for the statement.
Statement says is as follows:
m∠EBC + m∠CBA + m∠DBA = m∠EBD
From the above statement and figure its clear,
Sum of 3 interior angle is equal to exterior angle EBD.
This shows that Angle Addition Postulate is used.
Angle addition Postulate states that putting two angles side by side with their vertices together creates a new angle whose measure equals the sum of the measures of the two angles.
Therefore, Option C is correct.
