Respuesta :

Answer:

28.1 units

Step-by-step explanation:

Area of circle= πr², where r is the radius.

Given that the area is 20π,

20π= πr²

Divide both sides by π:

20= r²

Square root both sides:

[tex]r = \sqrt{20} [/tex]

[tex]r = \sqrt{4(5)} [/tex]

[tex]r = ( \sqrt{4} )( \sqrt{5} )[/tex]

[tex]r = 2 \sqrt{5} [/tex]

Circumference of circle= 2πr

Substitute the value of r:

Circumference of the circle

[tex] = 2(\pi)( 2\sqrt{5} )[/tex]

[tex] = 4\pi \sqrt{5} [/tex]

= 28.1 units (3 s.f.)