Answer:
Part 1) Greta's right, the triangle is incorrect.
Part 2)

Part 3) The height of the tree is
, Trey’s house is not at risk
Explanation:
Part 1) we know that
In the right triangle of the figure


Compare

therefore
The triangle is not correct
Because
The side adjacent to the 30 degree angle should be
and the side opposite the 30 degree angle should be

Part 2)
Let
x--------> the distance from the airplane to the SCCA (hypotenuse of the right triangle)
we know that



Part 3)
Let
x--------> the height of the tree
we know that



therefore
Trey’s house is not at risk