Beauty of this problem is all points are not in Same plane


The formula to calculate the distance between two points (x1,y1)(x1,y1) and (x2,y2)(x2,y2) is
d=(x1−x2)2+(y1−y2)2−−−−−−−−−−−−−−−−−−−√d=(x1−x2)2+(y1−y2)2.

Step 1) Distance between (0,0) and (0,a) using above formula = a
Step 2) Distance between (0,0) and (b,0) using above formula = b ( it could be height * because P(0,0) & (0,b) on same plane,x co ordinate is 0 fr both )
Drop a vertical line from (0,b) to bottom line to get height

Area = ab/2 = 6 => ab = 12 => a or b could be 3 , 4 or 4,3

c = Squart of ( 9 + 16) = 5

So, Perimeter = a+ b+ c side = 3+4+5 = 12