SOLUTION: The measure of the vertex angle (y) of an isosceles triangle is 20° more than twice the measure of each base angle (x). Use a system of equations to find x and y

Algebra ->  Triangles -> SOLUTION: The measure of the vertex angle (y) of an isosceles triangle is 20° more than twice the measure of each base angle (x). Use a system of equations to find x and y      Log On


   

Question 460229: The measure of the vertex angle (y) of an isosceles triangle is 20° more than twice the measure of each base
angle (x). Use a system of equations to find x and y
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!
 

            y° = 2x° + 20°
  x° + x° + y° = 180°

or

             y = 2x + 20
        2x + y = 180


Substitute 2x + 20 for y in the second equation:

2x + (2x + 20) = 180  
  2x + 2x + 20 = 180
       4x + 20 = 180
            4x = 160
             x = 40

Substitute 40 for x in 
    
             y = 2x + 20
             y = 2(40) + 20
             y = 80 + 20
             y = 100

So the base angles are 40° each 
and the vertex angle is 100°

Edwin