To factor out the coefficient of a variable you divide it by the sum.
You don't have the graph icon here, so we'll have to graph this parabola without it.
Your parabola is y = -x^2 + 3., which resembles y = a(x-h)^2 + k. We can tell immediately that this parabola opens down and that the vertex is (0,3).
Plot (0,3). Besides being the vertex, this point is also the max. of the function.
Now calculate four more points. Choose four arbitrary x-values, such as {-2, 1, 4, 5} and find the y value for each one. Plot the resulting four points. Draw a smooth curve thru them, remembering (again) that the vertex is at (0,3) and that the parabola opens down.
Circumference = 2*pi*r = 27"
Solve for r
r=27"/(2*pi)
=27"/(2*3.14159265)
=4.297..."
=4.30" (to the nearest hundredth of an inch)
24 + 100 is 124, and 124 x 2 = 248. So yes it is more than 120
