Final answer:
The third angle in a triangle with other angles measuring 80° and 50° respectively, is 50°. This is calculated using the triangle angle sum property.
Step-by-step explanation:
The subject of this question is Mathematics, more specifically it is dealing with the properties of triangles. According to the triangle angle sum property, the total sum of all angles in a triangle is 180°. If two of the angles are 80° and 50°, we can find the third angle by subtracting the sum of these two angles from 180°.
So, the calculation would be as follows: 180° - (80° + 50°) = 180° - 130° = 50°. The measure of the third angle in the triangle is therefore 50°. So, the correct option is A. 50°.
Learn more about Triangle Angle Sum