Answer:
4/9*pi or 1.395
Step-by-step explanation:
We have that area of the circle, that 4 * pi, we can calculate the radius of the circle, knowing that:
A = pi * r ^ 2
replacing:
4 * pi = pi * r ^ 2
r ^ 2 = 4 * pi / pi
r ^ 2 = 4
r = 2
Therefore, knowing the radius, we can calculate the perimeter:
P = 2 * pi * r
replacing:
P = 4 * pi
That is the perimeter of the whole circle, that is to say 360 °, therefore for 40 ° it would be:
4 * pi * 40 ° / 360 ° = 4/9 * pi
That is to say that the perimeter of the sector of 40 ° is 4/9 * pi, if pi is 3.14 it would be:
4/9 * 3.14 = 1.395
