Capacitance can be altered by bringing the two wire line close to ground.
(a) Apply the method of images to determine the Capacitance of the two-wire line, where the lower wire is suspended a distance from the PEC ground.
You must explain the steps you take to obtain the final equation. In other words, just giving me the final equation gets you zero points. Clearly label any images you have used and their distances from relevant points and clearly AND LEGIBLY show how these enter into the equation.
(b) For a sanity check let a=1m and calculate and compare the capacitance of the two wire line floating in space and placed above the ground.