A student writes an incorrect step while checking if the sum of the measures of the two remote interior angles of triangle ABC b
elow is equal to the measure of the exterior angle. A triangle ABC is shown. The base of the triangle extends into a straight line. The angle formed between this straight line and the edge of the triangle is marked as p. The angle adjacent to p is marked as o, and the other two angles inside the triangle are marked as m and n.
Please help, must be correct! In which step did the student first make a mistake and how can it be corrected?
Step 1; it should be m∠m + m∠n + m∠o = 180 degrees (sum of angles in a triangle)
Step 1; it should be m∠m + m∠n + m∠o = 90 degrees (adjacent angles)
Step 2; it should be m∠o + m∠p = 180 degrees (alternate exterior angles)
Step 2; m∠p − m∠o = 90 degrees (alternate interior angles)