The perimeter of the given triangle is the sum of the following segments:
Perimeter = PD + DO + OP
based on the given graph, you have that the coordinates of the points PDO are:
P: (1,-6)
D: (4,3)
O: (7,-6)
use the following formula for the distance in between two points:
d = √((x2 - x1)²+(y2 -y1)²)
where (x1,y1) and (x2,y2) are two points on the cordinate system.
For segement PD you have:
PD = √((1-4)²+(-6-3)²) = √(100) = 10
For segemtn DO:
DO = √((4-7)²+(-6-3)²) = √(100) = 10
For segment OP:
OP = √((1-7)²+(-6+6)²) = √36 = 6
then, the perimeter of the triangle is:
perimeter = 10 + 10 + 6 = 26