A 20 ft ladder is placed against a wall. The angle of elevation from
the ground to the ladder is 72°.
What is the distance from the foot
of the ladder to the wall? (Round
to the nearest tenth.

a≈380.13mi² would be your answer if the radius was 11 miles

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