What equation represents a circle with its centre at the origin, and a radius measuring 12 units

The equation is x² + y² = 144.

Step-by-step explanation:

This works the same way as before.

You know that at the origin, it equals (0, 0). So, we have no need to insert values for h and k. Therefore, it will just be x² + y² = r².

R is your radius, and this is given as 12 units. So, r = 12. Therefore, r² = 144.

Your final equation is x² + y² = 144.