Points D, E, and F are the midpoints of sides BC, CA, and AB, respectively, of triangle ABC respectively, and CZ is an altitude of the triangle. If angle BAC = 71, angle ABC = 39, and angle BCA = 70, then what is angle EZD+angle EFD in degrees?
In mathematics, you don't understand things. You just get used to them.
Of course that result can be rigorously obtained, but who cares?
Combinatorics is Algebra and Algebra is Combinatorics.