Answer:
The length of the missing side b would be 16m
Step-by-step explanation:
first you would use the formula a2+b2=c2
12^2+b2=20^2
-take 12*12 and 20*20
144+b2=400
-subtract 144 from 400 in order to get b2 alone
b2=256
-take the square root of b and 256
b=16
