Answer:
Option B. 2.2 miles.
Explanation:
A pilot of a small plane must begin a 10° descent starting from a height of 1983 feet above the ground that is AB is the height of plane above the ground, AB= 1983 feet. and A is the point from where the pilot starts descent.
thus, ∠ACB = ∠DAC = 10°
We have to find the distance between the runway and the airplane where it start this approach that is we have to find length AC( in miles).
Let AC = x
Applying trigonometric ratio,
![SinC=(Perpendicular)/(Hypotenuse)](https://img.qammunity.org/2019/formulas/mathematics/high-school/5prjtkvtjba0yhhwzqbk2lw1qi7zk1qb8v.png)
Put the values into the formula
sin 10° =
![(1983)/(x)](https://img.qammunity.org/2019/formulas/mathematics/high-school/g8e073jem8fy07xrmx53jiri2mqq3oo1dl.png)
0.1737 =
![(1983)/(x)](https://img.qammunity.org/2019/formulas/mathematics/high-school/g8e073jem8fy07xrmx53jiri2mqq3oo1dl.png)
x =
![(1983)/(0.1737)](https://img.qammunity.org/2019/formulas/mathematics/high-school/lc2y9vxfdaas3qzffdo4hyalp6zf9r0qd0.png)
x= 11419.64
The distance from the runway to the airplane is 11419.64 feet.
As we know 1 mile = 5280 feet
11419.64 feet =
![(11419.64)/(5280)](https://img.qammunity.org/2019/formulas/mathematics/high-school/gog0y4q3yt1rfnvgx9exvf6i3ft00ycitt.png)
= 2.16 miles ≈ 2.2 miles
Option B. 2.2 mi is the correct answer.