Solve this exercise using the fact that the sum of the measures of the three angles of a triangle is 180degrees°. In a triangle, the measures of the three angles are x, x − 21, and x - 12. What is the measure of each angle?
Add all of the angle measurements to equal 180 so the equation would look like x+x-21+x-12=180. Add all like terms and you’ll then get 3x-33=180. Next add 33 on both sides to get x by itself and then you’ll get 3x= 213. Next divide 3 on both sides to isolate x and you’ll get x=71. Substitute all values of x for 71.
