Same side interior angle the angle that formed by two parallel lines with a traversal (a line that cuts through the 2 lines) and the angle created between one of the parallel lines and the traversal. The angles that are between the parallel lines while being on the sames side of the traversal is same side interior angles. *The interior angles add up to 180 degrees.
The link will show numbers that represent the angles as an example. Numbers 3 and 6, 4 and 5 are interior angles.