Need help with these reasons and statements.

when the daily mileage is greater than 40 miles, unlimited mileage plan will save you money. 40 miles is the break-even point.

step-by-step explanation:

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