Aright triangle has a 50° angle. what is the measure of the third angle?
a. 180° b. 50°
c. 90°
d. 40°

Every triangle is 180 degrees.  A right triangle always has one angle that is 90 degrees (thus a right triangle).  Since you already now that two angles are 90 and 50, all you've got to do is find the third measure.  Now, add 90 and 50 which gives you 140.  Now you subtract 140 degrees from 180 degrees. This would be your answer, which is 40 degrees.

As you know, all angles add up to some total degree. For example, right angles need to be added up to 90 degrees. We all know a right angle is like the corner of this " L ". Subtract 90-50 is equal to 40 degrees. So all in all the third angle would be 40 degrees. Hope this helps!

This question is impossible to solve using the information you have provided for us.