Find surface area of a sphere with a circumference of 40ft

I came up with 509.3ft^2 does that sound right

Mrs Sue is a idiot

Mrs Sue is a i d i o t

r = c/2pi

a = 4pi*r^2 = 4pi(c/2pi)^2 = c^2/pi = 1600/pi

Steve would you possibly be abe to help me with this one?


Use formula to find the lateral area and surface prism area of the given prism.
height=2m
ends=7m and 7.28m
front=29m
not sure how to explain can give answer choices if that might help;
472m^2;486m^2
443m^2,486m^2
472m^2,479m^2
443m^2,500m^3

The volume of a sphere is 1,476 m (sqr 3). What is the surface area of the sphere to the nearest tenth?

V = (4/3) * pi * r^3

1,476m^(sqr3) = (4/3) * pi * r^3

r^3 = (1,476m^(sqr3) * 3) / (4 pi)

r = 13.8m (rounded to nearest tenth)

A = 4 * pi * r^2

A = 2,389.8m^2 (rounded to nearest tenth)

What is the scale factor of a cube with a volume of 729 m(sqr3)to a cube with a volume 6.859 m(sqr m)?

Let the scale factor be "x".

The volume of the smaller cube is 6.859 m³.
The volume of the larger cube is 729 m³.

Since volume of a cube is proportional to the cube of its side length,

(x * s)^3 = 6.859
s = cuberoot(6.859/x^3)

And,

(x * s)^3 = 729
s = cuberoot(729/x^3)

Equating s,

cuberoot(6.859/x^3) = cuberoot(729/x^3)

(6.859/x^3)^(1/3) = (729/x^3)^(1/3)

6.859^(1/3) / x = 9 / x

x = (6.859^(1/3)) * (1/9)
x ≈ 0.3

Therefore, the scale factor of the cubes is approximately 0.3.

O is the center of the given circle. The measure of angle O is 134 degrees. Assuming that lines that appear to be tangent are tangent, what is the value of x?