I need help solving for x

Answer:
[tex]x=63.0^o[/tex]
Step-by-step explanation:
Given
[tex]RS = 35[/tex]
[tex]RT = 77[/tex]
The attached triangle
Required
Solve for x
The relationship between x, RS and RT is:
[tex]\cos(x) = \frac{RS}{RT}[/tex]
This gives:
[tex]\cos(x) = \frac{35}{77}[/tex]
[tex]\cos(x) = 0.4545[/tex]
Take arc cos of both sides:
[tex]x = \cos^{-1}(0.4545)[/tex]
[tex]x=63.0^o[/tex] --- approximated