Final answer:
The value of the exterior angle a is 254°.
Step-by-step explanation:
The Exterior Angle Theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles. In other words, if we let 'a' be the measure of the exterior angle, and 'b' and 'c' be the measures of the two non-adjacent interior angles, then 'a = b + c'.
In the given information, we have '0 = 254°', which means that 'b = 0' and 'c = 254°'. Therefore, to find the value of 'a', we substitute the values of 'b' and 'c' into the equation 'a = b + c'. Thus, 'a = 0 + 254°', which simplifies to 'a = 254°'.