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
A scale factor of 3 means that the new shape is three times the size of the original. To calculate the Scale Factor, we use the following: You can get the 'big' and 'small' from the corresponding sides on the figures. So just get your # and multiply it by 3
Answer:
Considering the Law of Cosines:




Answer:
Look below
Step-by-step explanation:
Given that CDB is 90 degrees, ACB is 90 degrees, and ACD is 60 degrees, we can determine that DCB = 90-60 = 30 degrees.
This means triangle BCD is a 30-60-90 (angle measures) right triangle
The proportions of the sides (from smallest to largest) is
x:x√3:2x
We are given that BC = 6 cm. This means...
2x=6
x=3
This means DB is 3 cm and CD is 3√3 cm
Using the linear pair theorem, we can find that Angle CDA is 90 degrees. This means ACD is also a 30-60-90 triangle.
x=3√3
x√3=9
2x=6√3
Now we need to find AB
AB = AD + DB
AB = 9 + 3
AB = 12 cm

Answer:
160-128=32
Step-by-step explanation:
distribute what is in the parentheses