Question

Write the equation of a circle with center at (0, 0) and a diameter of 20.

A.
x2 + y2 = 100

B.
x2 + y2 = 20

C.
x2 + y2 = 10

D.
x2 - y2 = 400

Answer 1

If d=20 thn r=10
the equation of a circle is x²+y²=100
Answer A