A boy standing on the ground and flying a kite with 100m of string at an elevation of 30°. Another boy is standing on the roof of a 10m high building and is flying a kite at an elevation of 45 °. Both the boys are on the opposite sides of the kites. Find the length of the string that the second boy must have so that the two kites meet. °
Here is the answer to your query.
Let C be the position of the kite and A, B be the position of first and second boy respectively.
Let the length of the string (CD) with second boy be x metres.
Now CF = BC – BF = 50 m – 10 m = 40 m ( ∵ BF = DE = 25 m)
Hence the length of the string second by must have is metres.