What is the measure of the exterior angle x?

58°

80°

100°

180°

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%

Need 50 will mark brainliest answer. find the lengths of all the sides and the measures of the angles.