Answer:
radius = 4
Step-by-step explanation:
Recall that the equation of a circle centered at (0,0) on the plane is given by the formula:
[tex]x^2+y^2=r^2[/tex]
where "r" is the radius of the circle.
S, in our case, since the equation reads:
[tex]x^2+y^2=16[/tex]
16 corresponds to the square of the circle's radius. Therefore the radius can be found via:
[tex]r^2=16\\r=+/-\sqrt{16\\}\\r=+/-4[/tex]
and since we are talking about the length of a radius, we choose the positive option for the answer: radius = 4
