Question

[7.02] Which of the following is the equation for a circle with center (5, -1) and radius of 4?
A. (x + 5)2 + (y - 1)2 = 16
B. (x + 5)2 + (y - 1)2 = 4
C. (x - 5)2 = (y + 1)2 = 4
D. (x - 5)2 + (y + 1)2 = 16

Answer 1

just plug those values in

circumference of a circle = 2r π

area of circle = π r ^2

Answer 2

2 * r = d
2 * radius = diameter