Write the equation of a circle that has a center at the origin and a radius with a length of 4 inches

(x) ^2 + (y) ^2 = 4^2

Step-by-step explanation:

The standard form of an equation for a circle is

(x-h) ^2 + (y-k) ^2 = r^2

where (h, k) is the center and r is the radius

Since the center is 0,0 and the radius is 4

(x) ^2 + (y) ^2 = 4^2

x^2+y^2=16

Step-by-step explanation:

x^2+y^2=r^2 is the mother function of the equation of a circle centered at r with radius r

since r is defined to be 4 and 4^2 is 16 therefore, the equation would then be

x^2+y^2=16