Answer:
70
Step-by-step explanation: Triangle angle sum theorem states the interior angles of a triangle sum to 180 degrees. We know one angle is 40 degrees and the two remaining angles are equal in measure.
Since angle J and angle L are equal in measure we can substitute 2x for angles J and L into the equation.
40 + 2x = 180. Subtract 40 from both sides.
2x = 140. Divide both sides by 2.
X = 70