You have the next triangle:
As the triangle has two angles that are congruent, then it is a isisceles triangle. The opposite sides of the equal angles have the same measure.
Sides FG and GH have the same measure:
[tex]FG\cong GH[/tex][tex]x+40=2x+20[/tex]
Use this equation to find the value of x:
- Substract in both sides of the equation 2x:
[tex]\begin{gathered} x-2x+40=2x-2x+20 \\ -x+40=20 \end{gathered}[/tex]
- Substract in both sides of the equation 40:
[tex]\begin{gathered} -x+40-40=20-40 \\ -x=-20 \end{gathered}[/tex]
- Multiply both sides of the equation by -1:
[tex]\begin{gathered} (-1)(-x)=(-1)(-20) \\ \\ x=20 \end{gathered}[/tex]Answer x=20
