E and F- midpoints of sides AB and BC of triangle ABC. Find EF and BEF if AC = 14 cm and angle A = 72 degrees.

1) Since the points E and F are the midpoints of the sides AB and BC of the triangle ABC, the segment EF is the middle line of the triangle, parallel to the side of the AC and equal to its half: EF = AC / 2 = 14/2 = 7 cm.
2) Since the middle line EF is parallel to the AC side, the line AB is a secant for parallel EF and AC. In this case, the angles A and BEF are corresponding, and the corresponding angles are equal, so ∠A = ∠ BEF = 72 °.