HI,

I AM AFRAID THE ATTACHED QUESTION, WHICH I HOPE YOU CAN OPEN, HAS ME STUMPED A LITTLE.

I WOULD WELCOME ANY SUGGESTIONS THAT YOU MAY HAVE.

THANKING YOU IN ADVANCE AND HAVE A GOOD WEEKEND,

SHANE.

THE ANSWER TO PART (ii) OF THE QUESTION IS $\displaystyle \frac{a^2\sqrt{3}}{3}$