Final answer:
The measure of the third angle in the triangle is 75 degrees.
Step-by-step explanation:
In a triangle, the sum of all the angles is always 180 degrees. So to find the measure of the third angle, we can subtract the measures of the two given angles from 180 degrees.
The sum of the first two angles, 90 degrees and 15 degrees, is 105 degrees. Subtracting this from 180 degrees gives us the measure of the third angle, which is 75 degrees.
Therefore, the measure of the third angle is 75 degrees.
Learn more about Triangle angles