Question

Suppose that a satellite in space, an earth station and the centre of earth all lie in the

same plane. Let r be the radius of earth and R be the distance from the centre of earth

to the satellite. Let d be the distance from the earth station to the satellite. Let 300

be

the angle of elevation from the earth station to the satellite. If the line segment

connecting earth station and satellite subtends angle ∝ at the centre of earth, then

prove that

2

1 2 cos r r d R

R R

​

Answer 1

Answer:

In geometry, parallel lines are lines in a plane which do not meet; that is, two straight lines in a plane that do not intersect at any point are said to be parallel. Colloquially, curves that do not touch each other or intersect and keep a fixed minimum distance are said to be parallel.