Use numerals instead of words. If necessary, use / for the fraction bar(s). The expression above can also be written in the form Vad.
For this expression, a=, b=,c=

we know that

1) the inscribed angle measures half of the arc it comprises.

so

m∠dgf= > expression

2) the opposite angles in an inscribed quadrilateral are supplementary angles

so

m∠dgf=

m∠dgf=°

substitute in the expression to find the value of arc ef

therefore

the answer is

the measure of the arc ef is