Question 419460
In a case where you have ratios, you add the ratios together to get the total number of "units".  In this case, 13 + 16 + 21 = 50 "units".  Your first angle (13 "units") represents (13/50) of the total degrees in a triangle (which is 180).  So, the first angle is (13/50) * 180 = 46.8 degrees.  Your second angle (16 "units") represents (16/50) of the total degrees in a triangle = (16/50) * 180 = 57.6 degrees.  Your last angle (21 "units") represents (21/50) of the total degrees = (21/50) * 180 = 75.6 degrees.

Let's see if we get the total right:

46.8 + 57.6 + 75.6 = 180 which is the right number of degrees in a triangle.

So, the angles are 46.8 degrees, 57.6 degrees, and 75.6 degrees.