What are the angle measurements in the triangle?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

What is the missing reason in the proof? segment addition congruent segments theorem transitive property of equality subtraction property of equality?