Answer:
the perimeter is 30ft
Explanation:
a square + b square = c square
so first we find your missing side
this is how we solve for that:
a square + 12 squared = 13 squared
a squared + 144 = 169
now we do 169 - 144 = 25
now to find the missing side it is 25 square root which is 5
now that we have found the missing side lengths let's find the perimeter which is: 5 + 12 + 13 = 30 ft
I hope this helped!