Look at the photo i placed below for further info

In order to find the value of x, we need to remember that the sum of the interior angles of a triangle is 180°
the equation to find x is
[tex]61+29+x=180[/tex]we need to isolate the x
[tex]\begin{gathered} x=180-61-29 \\ x=90 \end{gathered}[/tex]the answer is c x=90°