Hey there :)
Both are congruent figures which means they share the same angle measurements.
We have 3 angles given,
∡A and ∡J = 133°
∡D and ∡M = 86°
∡C and ∡L = 41°
∡B and ∡K = ?°
Add them and subtract it from 360° since the total angle measurement equals to 360°
86 + 41 + 133 + x = 360
260 + x = 360
360 - 260 = 100
The missing angle is 100°