Answer:
65°
Step-by-step explanation:
JM = JK (all sides of a rhombus are equal)
Angle JKM = 25° (isosceles triangle)
Angle JKL = 50° (consecutive angles of rhombus)
Angle MKL = 25° (angle subtraction)
Angle MLK = 130° (opposite angles of a rhombus)
Angle KLN = 50° (angles on a straight line)
Angle LKN = 40° (angle sum of triangle)
Angle MKN = 65° (angle addition)