Triangle K M L is shown. Line L K extends through point J to form exterior angle J K M.

Question

Which angle is an adjacent interior angle to ∠JKM?

∠JKL
∠MKL
∠KLM
∠LMK

Answer 1

In triangle KML, when you extend line LK through point J to form the exterior angle JKM, the adjacent interior angle to ∠JKM would be the angle that shares the vertex K and is between the sides of the triangle KML.

The angles in triangle KML at vertex K are ∠KLM and ∠MKL. Therefore, the angle that is adjacent to ∠JKM is the one that shares the vertex K and is part of triangle KML.

Thus, the adjacent interior angle to ∠JKM is ∠MKL.