Question

the relation between an exterior angle and interior angle of an triangle.

Answer 1

An exterior angle of a triangle is equalto the sum of the opposite interior angles. For more on this see Triangle external angle theorem. If the equivalent angle is taken at each vertex, the exterior angles always addto 360° In fact, this is true for any convex polygon, not just triangles

Answer 2

relation between exterior angle and interior angles of the triangle is

sum of two interior angles opposite to the side corresponding to exterior angle is equal to exterior angle

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