Answer:
(x + 4)^2 + (y - 8)^2 = 81
or
(x + 4)^2 + (y - 8)^2 = 9^2 depending on how your teacher wants it written.
Step-by-step explanation:
The standard form for a circle is
(x + h)^2 + (y + k)^2 = r^2
r is the radius.
You are given the diameter
r = d/2
r = 18/2
r = 9
So you already have the right hand side of the equation
(x + h)^2 + (y + k)^2 = 9*2
(x + h)^2 + (y + k)^2 = 81
You basically have h and k as well. They come from the center point.
h = 4
k = - 8
So the equation of the circle (and the answer) is
(x + 4)^2 + (y - 8)^2 = 81
One question remains. Why do the x and y values change signs? If you know what the distance formula is, then what you are finding is the distance r of all points on the circle from the center of the circle.
It is the distance formula that is actually the formula for the circle.
Subtract 1 to 13. so you got 12. divide 4 so you can get the S by it self.S=3.
First you want to find the surface area of one box
SA=2(l*w)+2(h*l)+2(h*w)
SA=2(12*12)+2(15*12)+2(15*12)
SA=2(144)+2(180)+2(180)
SA=288+360+360
SA=1008 cm² is for one box
Multiply by 4 to get for 4 boxes
4*1008=4032 cm²