The elevation angles of the tree top from Kevin and Lisa standing on the ground are respectively 40° and 30°. The bearings of Kevin and Lisa from the tree foot are respectively due East and SE.
If the tree is 20m high, how far apart are Kevin and Lisa, correct to the nearest metre?

Question

anonymous · Answer

631.891 meters

mimi_x3 · Answer

Um, how did you get the answer ?

anonymous · Answer

distance of Kevin from tree x = 20/tan(40)=23.835
distance of Lisa from tree x = 20/tan(30)=34.641

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distance between Kevin and Lisa = 34.641^2 - 23.835^2

=631.891 meters