Answer:
(1.5, -13.5)
Step-by-step explanation:
Midpoint Formula: 
Simply plug in our coordinates into the formula:
x = (17 - 14)/2
x = 3/2
y = (-11 - 16)/2
y = -27/2
What variable are you solving for?
$2.6, multiply 13 by .2 and you get 2.6
Since it's an equilateral triangle, all of the angles are the same. Since its perimeter we just need to add. So 3.5+3.5+3.5= 10.5
So the answer is 10.5