Each side of the pentagon is extended (dashed) to show its exterior angles. Four of them are 72°, 80°, 60° and 63°. Find the fifth exterior angle $x$.

**The sum of the exterior angles of any convex polygon (one at each vertex) is always 360°** — no matter how many sides.

For a regular n-gon, each exterior angle = 360°/n. So a regular quadrilateral (square) has exterior angle 360/4 = 90°. A regular pentagon: 72°. A regular hexagon: 60°.