Final answer:
To find the value of x in triangle ABC, we can use the fact that the sum of the angles in a triangle is 180°. By setting up an equation and solving for x, we find that x is approximately 46.67°.
Step-by-step explanation:
The given problem has a triangle ABC, where angle C is 40°, angle B is x, and the measure of the exterior angle A is 2x. To find the value of x, we can use the fact that the sum of the angles in a triangle is 180°.
So, we have 40° + x + 2x = 180°. Simplifying this equation, we get 3x + 40° = 180°. Subtracting 40° from both sides, we have 3x = 140°. Finally, dividing by 3, we find that x = 46.67°.
Therefore, the value of x in ∆ABC is approximately 46.67°.