To find the measure of the third angle $x$ in the triangle, we can use the fact that the sum of the angles in any triangle is always 180°.

The angles provided are 125° and 27°.

Let's set up the equation:

$125^\circ + 27^\circ + x = 180^\circ$

Now, solve for $x$:

$x = 180^\circ - 125^\circ - 27^\circ$

$x = 180^\circ - 152^\circ$

$x = 28^\circ$

Therefore, the measure of the third angle is 28°.

The correct answer is B. 28°.

Would you like more details, or do you have any questions about this?

Here are 5 follow-up questions related to this topic:

1. What is the general formula for the sum of angles in a polygon?
2. How do you classify a triangle with an angle larger than 90°?
3. What is the difference between an acute and obtuse triangle?
4. Can a triangle have more than one obtuse angle? Why or why not?
5. How would you calculate the missing angle if given an exterior angle of the triangle?

Tip: Always remember that the sum of the angles in any triangle is 180°, and this is key to solving many triangle-related problems.