Answer:
x = 21
Step-by-step explanation:
We have alternative external corners.
The lines m and n are parallel. That is why the alternative external angles are congruent (they have the same measure).
In the triangle RTS we have angles:
[tex]4x^o,\ 54^o,\ 2x^o[/tex]
We know: The sum of the angles of the triangle is equal to 180 °.
Therefore we have the equation:
[tex]4x+54+2x=180[/tex] subtract 54 from both sides
[tex]6x=126[/tex] divide both sides by 6
[tex]x=21[/tex]
