2rational numbers that are not integers

Me #1 using vocabulary words, including the word “congruent”, state why the measure of angle d is 120 degrees. #2 what is the measure of angle e and why?

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

The median of a data set is the measure of center that is found by adding the data values and dividing the total by the number of data values that is the value that occurs with the greatest frequency that is the value midway between the maximum and minimum values in the original data set that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude