Given:
The equation of the circle is:
To find:
The radius of the circle.
Solution:
The standard form of a circle is:
...(i)
Where, (h,k) is the center and r is the radius.
We have,
In can be written as:
...(ii)
On comparing (i) and (ii), we get
Here, the center of the circle is the origin and the radius is equal to 4 units.
Therefore, the radius of the given circle is 4 units.