Can someone me and explain how they did it?

The sum of the interior angles of this shape is 360 degrees. You would do 133 + 86+41 and then subtract the sum from 360. You get 100° as the answer

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°