let's recall that a Centroid in a triangle cuts the Medians into a 2:1 ratio, or namely CG : GD are in a 2: 1 ratio, we can also look at it that the side CD is 2/3 of CD whilst GD is 1/3 of CD, so

The perimeter is everything added up, since its not a square then you add not multiply. 24+24=48 and 16+16=32, add 32 and 48 and get 80. Answer:80