algebra and radius help?

The radius of a circle is the distance from its center to its boundary.

pi = 3.14 always

Area of a circle = (pi) x radius^2

Circumference of a circle = 2(pi)xradius

if radius = 2cm, then

Area = (pi) x 2cm^2

Area = 3.14 x 2cm^2

Area = 12.56 cm^2

Circumference = 2 x 3.14 x 2cm

Circumference = 12.56 cm

20-3k = 6k +2

20-2 = 6k+3k ====> first we move all variables to the same side

18=9k

(18/9) = k

2=k

0:

radius is the distance from the center to the circle

π is a constant approximately equal to 3.1415926535897932384626433832795...

1:

πr²=π(2²)=4π cm²

2:

π2r = π(2*2) = 4π cm

3:

20 - 3k = 6k + 2

18=9k

k=2

Radius is half the diameter and the circumference is 3.14 times the diameter

Hope this helps :)