I need help? With angles of triangles

50

Step-by-step explanation:

So triangle angles add up to 180. You already have 91 so try finding the other angles. you have an angle outside of the triangle that is 141. That angle supplementary which means they add up to 180. Take 180 minus 141 to get 39. Thats your second angle inside the triangle. Add 39 plus 91 to get 130. 180 minus 130 is 50 which is your final angle.