StatementReason m∠ADE = 36°Given
m∠DAE = 90°Definition of a right angle
m∠AED = 54°Triangle Sum Theorem
segment DE joins the midpoints of segment AB and segment ACGiven
segment DE is parallel to segment BC?
∠ECB ≅ ∠AEDCorresponding angles are congruent
m∠ECB = 54°Substitution property

Which theorem can be used to fill in the missing reason?
Concurrency of Medians Theorem
Isosceles Triangle Theorem
Midsegment of a Triangle Theorem
Triangle Inequality Theorem