Theory:

Let us see some more pairs of angles, in this lesson.
1. Co-interior angles:
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Each pair of angles named \(∠3\) and \(∠6\), \(∠4\) and \(∠5\) are marked on the same side of transversal line \(l\) and are lying between the lines \(m\) and \(n\). These angles are lying on the interior of the lines \(m\) and \(n\) as well as the same side of the transversal line \(l\). So these are called as co-interior angles.
2. Co-exterior angles:
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Each pair of angles named \(∠1\) and \(∠8\), \(∠2\) and \(∠7 \)are marked on the same side of transversal line \(l\) and are lying outside of the lines \(m\) and \(n\). These angles are lying on the exterior of the lines \(m\) and \(n\) as well as the same side of the transversal line \(l\). So these are called as co-exterior angles.