Assuming the equation of the circle should be
(x + 3)² + (y - 4)² - 16
the equation of a circle in standard form is
(x - a)² + (y - b)² = r²
where (a, b) are the coordinates of the centre and r is the radius
(x + 3)² + (y - 4)² = 16 is in this form
with r = [tex]\sqrt{16}[/tex] = 4
the circumference( C ) of a circle = 2πr = 8π ≈ 25.1
