Interior Angles

Solve mathematical problems involving interior angles (medium)

Find the value of each variable, then find the interior angles of each triangle.

\(m \angle N = (8 a - 86)^\circ,\) \(m \angle O = 63^\circ,\) \(m \angle P = 67^\circ\)

Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles. For example, arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so.