Answer:
120°
Explanation:
I drew a picture that will make it easier to understand what's going on. Please see the attached image
In a rhombus, the diagonals bisect the opposite angles, and opposite angles are congruent.
Let's say angle 1 is x. The interior angles of a quadrilateral add up to 360°, so
30+30+30+30+2x=360
2x=240
x=120
angle 1 is 120°.