Answer:
60°, 60° and 120°.
Explanation:
ABCD is a parallelogram in which one angle is 120°. 
We know that, 
- opposite angles of Parallelogram are equal.
- Sum of all the angles of Parallelogram is 360° 
Let us take 
 is 120°
 is 120°
As 
 and
 and 
 are the opposite angles so they will be equal.
 are the opposite angles so they will be equal.
 = 120°
 = 120° 
Sum of all the angles of Parallelogram is 360°.





 B and
 B and 
 C are also the opposite angles so they will be equal. Let us consider
 C are also the opposite angles so they will be equal. Let us consider 
 B and
 B and 
 C be x
 C be x 


 
 
Hence, 
 = 60°
 = 60°
 = 60°
 = 60° 
Therefore, the other three angles of the Parallelogram are 60°, 60° and 120°.
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