Answer:Radius=2
Step-by-step explanation:
2g=4
g=4/2
g=2
2f=-2
f=-2/2
f=1
c=1
Radius=√(g^2+f^2-c)
Radius=√(2^2+(-1)^2-1)
Radius=√(4+1-1)
Radius=√(4)
Radius=2
