Answer:
m∠1 = 30°
Explanation:
Properties of a rhombus,
1). Sum of adjacent angles is 180°.
2). Diagonals bisects the angles of a rhombus 
By property - (1)
m∠M + m∠N = 180°
120° + m∠N = 180°
m∠N = 180 - 120 
 = 60°
By property - (2)
Diagonal PM will bisect the angle M.
m∠1 = m∠2 
m∠1 = 

 = 

 = 30°