Question

what is $mwidehat{tu}$?
$mwidehat{tu} = \square ^\circ$
the circle has arcs: $overset{\frown}{st}=50^\circ$, $overset{\frown}{uv}=120^\circ$, $overset{\frown}{vs}=135^\circ$

Explanation:

Step1: Sum all given arc measures

$50^\circ + 135^\circ + 120^\circ = 305^\circ$

Step2: Subtract from total circle degrees

A full circle is $360^\circ$, so:
$360^\circ - 305^\circ = 55^\circ$

Answer:

$55$