Answer:
The third angle is 47 degrees
Step-by-step explanation:
It says in the question that it is a "right triangle", so that means that there has to be one 90 degree angle (right angle). A triangle's angles always add up to 180 degrees so you can just add 90 and 43 and subtract the sum from 180:
180 - (43 + 90) = a
180 - 133 = a
47 = a
That means that the third angle is 47 degrees.