Answer:
31.96 centimeter is the answer
Firstly, we need to draw triangle
we know that
O is a centroid
and centroid divides median into 2:1
so,

we have FO=4
so, we can plug it


now, we can find CF
CF=OC+FO
CF=8+4
CF=12
now, we can see triangle ACF is a right angled triangle
so, we can use pythagoras theorem

now, we can solve for x



Since, it is equilateral triangle
so,

we know that
E is a mid-point
so,

now, we can plug values

................Answer
Divide 1.28 by 2 answer .64 notepads divide by 3. u get .29 each so add .29 twice. u get .58 add 1.59 twice. u get 3.18. pens 1.98. add .64 + .58 + 3.18 + 1.98= 6.38 so answer is A