Determining Acceleration of Hinge in a Beam and Hinge Structure

[Carbon123]

Homework Statement

The following structure,A force F is applied to the right hinge.If the mass of the rods are equal ,and the length of the rod is equal,the intial angle is also equal to 90 degrees (a square),What is the intial acceleration of leftmost hinge ?

Homework Equations

Coordinate systems ,differentiation

The Attempt at a Solution

I am quite confused of where to start this problem.I think that stating the coordinates of the hinges,and then differentiating it to find the relation of acceleration.However, I keep getting that the acceleration is the same.Can someone please advise me some idea where to start ,and what principles are at work here.I have not got any idea (due to being inexperienced with problems with hinges like this).Thanks in Advance !

 

[haruspex]

However, I keep getting that the acceleration is the same.

Please post your working (as required by forum rules).
Have you analysed the forces on one of the left hand members and one of the right hand members as separate rigid bodies?