https://decimal-to-binary.com/ploschad-kruga.html?id=3

krgua area with diameter 30 equal to 706.838

Method of calculating the area of the circle
Diameter d:

Circle (circle)

A circle (circle) is a geometric figure on a plane, all points of which are equidistant from a given point (the center of the circle).
Circle area formula Formula for the area of a circle through diameter where d is the diameter of the circle

Solution:
S =
π·
d2
4
=
3.1415·
302
4
=
3.1415·
900
4
=
3.1415·
225
=
706.838

Answer: krgua area with diameter 30 equal to 706.838