Answer:
x = 49°
Step-by-step explanation:
Angles in a Triangle
The sum of the internal angles in any triangle adds up to 180°.
The figure shows a triangle that includes two angles with the same tick mark. This means they are congruent, i.e. they measure the same.
The larger triangle has three defined angles: 43°, 39°, and 2x. Since the sum of them is 180°:
43° + 39° + 2x = 180°
Operating:
82° + 2x = 180°
Subtracting 82°:
2x = 180° - 82° = 98°
x = 98°/2 = 49°
x = 49°
