A beverage manufacturer is mixing up a 31% tomato juice blend. The manufacturer already has 440 gallons of a blend that contains 40% juice, to which some 10% juice will be added. How much should be added to obtain the 31% tomato juice that is desired?

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