SOLUTION: it a triangle has two angles of equal measuer, then the thrid angle is what?

Algebra ->  Geometry-proofs -> SOLUTION: it a triangle has two angles of equal measuer, then the thrid angle is what?      Log On


   

Question 117566: it a triangle has two angles of equal measuer, then the thrid angle is what?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=measure of angle 1, y=measure of angle 2, and z=measure of angle 3,

Since two angles are equal to one another (say the first two), this means that y=x. Now remember, the sum of the angles of a triangle is always 180 degrees. In other words,


x%2By%2Bz=180


But remember, y=x. So we can replace y with x to get


x%2Bx%2Bz=180


2x%2Bz=180 Combine like terms


z=180-2x Subtract 2x from both sides to isolate z (which is the third angle)


So the third angle can be found through the formula

z=180-2x if the first two angles are equal.