Answer:
centre = (0, 0 ), radius = 5
Step-by-step explanation:
The equation of a circle centred at the origin is
x² + y² = r² ( r is the radius )
x² + y² = 25 ← is in this form
with centre = (0, 0 ) and r = = 5
I can't see a square or a D given with your question.
But to find the perimeter you just have to add the surface of every side of the square.
8
round each number to the nearest 10, then
640 ÷ 80 = 8 ← estimate
= 5
