Question 1035787
This has to be drawn.
There is a line from the plane to the distant ship with depression 25 degrees.  Call this line c.  We know the distance to that ship for a right triangle formed by the ship to the plane's height (265 m) the course of the plane and c. The sin 25=265/c, and c=265/sin (25),  or 627.04 m.
===========
Similarly, for the closer ship, there is line a, its distance from the plane, which is 265/sin(35)=462.01 m. This is line a.
Let b be the line between the ships.  Angle A is the angle between the ship and the plane, which is 25 degrees (alternate interior angles). Angle B, opposite to the inter-ship distance, is 10 degrees, the difference in depression angles.  Angle C is their sum subtracted from 180 degrees, or 155 degrees.
=====================
Use law of cosines for side b
b^2=a^2+c^2-2ac cos B
b^2=462.01^2+627.4^2-2(462.01)(627.04)cos(25)
=606632.4-525112.5=81,519.9
b=285.5 m