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 50
Step-by-step explanation:
You add up all the numbers and divide the numbers by how many numbers there are.
Answer:
120°; 240°
Step-by-step explanation:
Let's first solve for
:
At this point it's just a matter of drawing a circle, and mark where the angle is(please excuse my paint skills, but free hand drawing would be even worse). Red line, is
on the cosines, and both the green and blue lines are valid solutions. The green line is a quarter of a circle, plus 30°, or 120°. The blue one is 3/4 of a circle, minus 30 degrees, or 240°.
Answer:
The faster train goes 60mph
Step-by-step explanation:
s= speed
s+20 is the faster train.
Then you are given:
200/s+s+20=2
200=2*(2s+20)
4s+40=200
4s=160
s=40 is the slower train
40+20= speed of faster one
s=60 ;)
Answer:
<h2>
43°</h2>
Step-by-step explanation:
In a cyclic quadrilateral, the sum of two opposite angles are equal.
m<R + m<P = 180°
plugging the values:
3y + 8 + y = 180°
Combine the like terms:
4y + 8 = 180°
Subtract 8 on both sides
4y + 8 - 8 = 180 - 8
Calculate the difference
4y = 172
divide both sides of the equation by 4
4y/4 = 172/4
calculate
y = 43°
Hope this helps...