Respuesta :

Answer: 5 units

Step-by-step explanation:

The standard form of equation of circle:

[tex](x-h)^2+(y-k)^2=r^2[/tex] , where (h,k) = center of circle, r= radius.

Given : Center of circle= origin = (0,0) =(h,k)

Point on circle = (3,4)

Put x= 3 , y=4 , h=0 , k=0 , then the equation will become

[tex](3-0)^2+(4-0)^2=r^2\\\\\Rightarrow\ 9+16=r^2\\\\\Rightarrow\ 25=r^2\\\\\Rightarrow\ r=5[/tex]

Hence, the radius is 5 units long.