Answer:
m = 36
Step-by-step explanation:
A^2 + B^2 = C^2
81 + 144 = 225
square root of 225 = 15
n = 15
m = ?
39 = 39
225 + m ^2 = 1521
m^2 = 1296
m = 36.
CHECK :
225 + 1296 = 1521
CORRECT!
