Answer:
∠2 = 50°
Explanation:
The marked sides tell you all of the sides of this quadrilateral are the same length. That means it is a rhombus. The diagonals of a rhombus meet at right angles, and opposite sides are parallel (it is a parallelogram).
That means the angle at top right is congruent to angle 2, hence complementary to angle 1.
∠2 = 90° -∠1
∠2 = 90° -40° = 50°