Answer:
16 + sqrt(128)
Explanation:
find the lengths of all 3 sides:
the side from (-9,8) to (-9,16) will be 16-8=8 (x stays constant)
The side from (-9,8) to (-17,8) is 8 (-9- (-17)=8)
The side from (-9,16) to (-17,8) will be found from the distance formula
d=sqrt((-17-9)^2 + (8-16)^2))
= sqrt(128)
So the perimeter will be these 3 numbers added together
P=sqrt(128) + 8 + 8
= 16 + sqrt(128)
which can simplify to:
= 16 + 4sqrt(8)
= 16 + 8sqrt(2) = 8+ sqrt(2)