If a triangle has angles measuring 60 degrees and 90 degrees, what is the measure of the third angle?

To determine the measure of the third angle in a triangle, it's important to remember that the sum of the angles in any triangle is always 180 degrees. In this particular case, you have two angles measured at 60 degrees and 90 degrees.

First, add the measures of the provided angles:

60 degrees + 90 degrees = 150 degrees.

Now, subtract this sum from 180 degrees to find the measure of the third angle:

180 degrees - 150 degrees = 30 degrees.

Thus, the measure of the third angle in the triangle is 30 degrees. This confirms that the choice indicating the third angle as 30 degrees is indeed the correct answer.