Atriangle has angles measuring 15° and 45°. what is the measure of the triangles third angle

For this, we need to know the measure of all the angles in a triangle together: 90 degrees.
With this information, we can set up an equation: 90 = 15 + 45 + x
15+45 = 60
90-60 = 30
Therefore, your third angle is 30 degrees.

Every angle equal 180 . Therefore, 15+45=60. 180-60= 120. Your answer would be 120.

Sorry sir you did not give us the graph i typically but i'm very confused my conclusion is you're missing valuable information in the question