Question

A kite flying at a height of 45m from the level ground is attached to a string inclined at 60 degree to the horizontal. The length of the string is?

Answer 1

You can use this easy method
Height = 45m
Angle (@) say = 60°
Now
we have a formula for this
height = length of string × sin@
length of string = height / sin@
length of string = 45/sin60° = 45/ (root3/2) = 45/0.866 = 51.96 m is the right answer

Answer 2

$\large{ \frac{45}{AB}}=$${ \frac{root 3}{2}}$
$AB=\large{ \frac{90}{root 3}} \\\\ AB = \large{\frac{90}{1.73} = 52.23\:m}$