Answer:
Step-by-step explanation:

Formula to find the mid-point is
.
We need to find the mid-point of HG where H(0,0) and G(2a,0). So, now we can plug in x1=0, y1=0, x2=2a and y2=0 in the above formula to get the answer. So, mid-point of HG is,
.
=
=(a,0).
So, mid-point of HG is (a, 0).