"Formula of a circle" is too vague to be meaningful. Perhaps you meant, "Formula for the area of a circle in terms of its circumference."
The area of a circle in terms of its radius is A = πr^2. To put this formula to use, we have to know the radius of the circle. The circumference of a circle in terms of its radius is C = 2πr, so a formula for the radius is r = C / (2π).
Now let's find a formula for the area of a circle in terms of its circumference:
C C^2
A = πr^2 = π { ---------------- }^2 = ------------
2π 4π
or:
A = (C^2) / 4π
Answer:
x=5
Step-by-step explanation:
-12=8-4x
-20=-4x
5=x
Answer:
Cost price=100%
Step-by-step explanation:
Answer:m<2= 160 degrees m<3=20 degrees
Step-by-step explanation:the angles have to equal 360 in all and the side lengths are all the same
The amount of metal used to make the can = surface area of cylindrical can, which is: D. 42π in².
<h3>What is the Surface Area of a Cylinder?</h3>
A can is a cylinder.
Surface area of a cylinder = 2πrh + 2πr²
Thus:
Amount of metal used to make the can = surface area of the can
r = 6/2 = 3 in.
h = 4 in.
Therefore:
Surface area = 2×π×3×4 + 2×π×3²
Surface area = 24π + 18π
Surface area = 42π in².
Learn more about the surface area of a cylinder on:
brainly.com/question/14657844
