Look it up :)))))))))))))
Answer:
9 M
Step-by-step explanation:
a^2+b^2=c^2
12^2+b^2=15^2
144+b^2=225
-144 -144
b^2=81
b=sqrt of 81
b=9
The answer is 27. I figured that out by multiplying 9x12 so that I could convert nine feet to inches. That equaled 108. After that, I divided that by 4 to see how much years it would take and it was 27 years.