Question 307982:  if two angles of a triangle measure 40 degrees and 70 degrees, what is the measure of the third angle? 
 Answer by rapaljer(4671)      (Show Source): 
You can  put this solution on YOUR website! The sum of the angles of a triangle is 180 degrees.  To find the third angle, add the first two together, and subtract this from 180.
 
 
In this case, 40+70=110.  Subtract 180-110= 70 degrees.
 
 
As a check, add the three angles and see if it comes out to 180 degrees. 
40+70+70= 180, so it checks.
 
 
Dr. Robert J. Rapalje, Retired 
 
  | 
 
  
 
 |   
 
 |