Answer: 39.58 cm
Step-by-step explanation:
The circumference of a circle is 2 times the radius times pi or pi times the diameter. so we know the diameter is 12.6 so just multiply it by pie.
12.6 * pi = 39.584
Now rounded to the nearest hundredth is 39.58.
Okay, first, given the equation, we need to find out what the radius of the circle is. Let us state the general equation of a circle:

Where

is the centre of the circle. In this case, we don't need to know the centre. Just the radius.
Let us start by converting the equation into standard for, which I typed above. Divide both sides by 81.

Great! We now know the radius of the circle. It is

because it is the bottom fraction. Now we know that the radius is 9.
So now lets input this into the area of circle formula:
Now we insert our radius.
You can convert that into a decimal if you wish.
Hope this helped!
~Cam943, Moderator
Answer:
The answer is 96 cm^2
Step-by-step explanation:
A cube can be seen as a 3D shape formed by sticking together 6 squares.
So the surface area would be the area of one of those squares multiplied by 6.
Then
16 cm^2 * 6 = 96 cm^2
Answer: 81 cm
Step-by-step explanation:
You would get this because if 1 cm = 4 meters than divide 324 meters by the 4 meters to find how many cm there is and you will get 81 cm hope this helps and have a good day