sorry wait please delete my answer I realized my mistake!
Factors of 12 : 1, 2, 3, 4, 6, 12
Factors of 20: 1, 2, 4, 5, 10, 20
In both lists of factors, 4 is in common. Therefore, the value of K is 4 because it can divide into both 12 and 20 without a remainder. 2 is also another possible value of K.
To find the area of the circle, you will use the formula for finding area of any circle.
The radius is half the diameter.
A = pi x r^2
3.14 x 13^2
A = 530.66 square units
The area is 530.66 square units.