Answer:
36
Step-by-step explanation:
So to find the last angle first. The formula is a power 2+b power 2=c power 2
So 9 power 2 is 81 and 12 power 2 is 144
144+81=225
the square root of 225 is 15. So x is 15
No we just have to do 9+12+15=36.
36 is the perimeter
