IMO A.

If you draw out a triangle with base at (0,0) and (6,0), the avg of the those two points is the x co-ordinate of the center.

in this case, the center point of which is (3,2) has the x co-ordinate of 3.

halfway between the base is 3.

2 is the y co-ordinate for the center which means it must be halfway in between 0 and 4.

so the height is (3,4)

what is the OA?

It should be (3,6). It is asking coordinate of the other third vertex.

Xcenter = avg of the x coords of T
Ycenter= avg of the y coords of T

(x1+x2+x3)/3=3=> x3=3

similarly
(y1+y2+y3)/3=2=> y3=6

(3,6)

rah_pandey wrote:It should be (3,6). It is asking coordinate of the other third vertex.

Xcenter = avg of the x coords of T
Ycenter= avg of the y coords of T

(x1+x2+x3)/3=3=> x3=3

similarly
(y1+y2+y3)/3=2=> y3=6

(3,6)

rah_pandey, you're right! OA is (3,6)