Question 1014440
DRAW the figure.
Two right triangles share the same leg of 12 meters for the tree height.  One triangle has short unknown leg where Mazaheer is, the 67 degree elevation to tree top, and longer unknown leg where Trinia is, the 53 degree angle of elevation to the tree top.  The point of the tree base, point where is Mazaheer and point where is Trinia, are on the same line (collinear).


Mazaheer:
{{{tan(67)=12/M}}}
{{{M*tan(67)=12}}}
{{{M=12/tan(67)}}}


Trinia:
{{{tan(53)=12/T}}}
{{{T*tan(53)=12}}}
{{{T=12/tan(53)}}}


How far apart are they?
{{{T-M}}}
{{{12/tan(53)-12/tan(67)}}}-----this uncomputed expression is how far apart the two girls are on the ground.  This itself was not what was the question.  Neither is this really necessary...


How far is Trinia from the top of the tree?
This is the hypotenuse of the right triangle so, ....  USE sine function.
Let r be the distance from Trinia to the tree top.
{{{highlight(sin(53)=12/r)}}}
THAT is what you want, and solve for r.