△ABC is similar to △DEF by the AA Similarity Postulate .

What is the measure of ∠C?

Because △ABC is similar to △DEF, angle ABC should equal 60 deg as well.

\(\boxed{ \text{The sum of all interior angles of a triangle is 180}^{\circ}}\)

So Angle C = 180 - 55 - 60 = 65 deg :D