Respuesta :

Answer:

radius = 2

Step-by-step explanation:

The equation of a circle centred at the origin is

x² + y² = r² ( where r is the radius )

x² + y² = 4 ← is in this form

with r² = 4 ⇒ r = [tex]\sqrt{4}[/tex] = 2

centre (0, 0 ) and radius = 2