Question

An observer (O) spots a plane flying at a 55° angle to his horizontal line of sight. If the plane is flying at an altitude of 21,000 ft., what is the distance (x) from the plane (P) to the observer (O)? (4 points)

Answer 1

If the plane is flying at an altitude of 21,000 feet, it is perpendicular to the observer's horizontal line of sight. Thus, I concluded that the given information be assigned to the attachment below.

Given -

( Observer at point O, plane flying at point P

( Plane at 55° angle to horizontal line of sight, altitude of 21,000 feet

The distance ( x ), is represented by the line segment OP, with which we have to determine the length of. Therefore we can conclude the following -

$Sin( 55 ) = Altitude / Distance,\\Sin( 55 ) = 21,000 / x,\\----------------\\x = \frac{21,000}{Sin( 55 )},\\x = 21,000 / 0.81915204428\\\\x = ( About ) 25636 feet$

As you can see, the distance from the plane to the observer is about 25,636 ft!