What is the lateral area of the cone? base 10 yd height 12.1 yd a. 242.6 yd2 b. 190.07 yd2 c. 603.19 yd2 d. 96.4 yd2 me get this answer correct ! asap

To get the area of the lateral side of a cone you will need the formula:

L= r x  x l

where: L = Lateral area
            l  = length or height
            r = radius
            = 3.1416
Now sorting out your given:
base = 10 yd
Height = 12.1 yd

To work out the lateral area, you will need the radius. Your base 10 yd, is the measure from one side to the other of the circle base, this is what you call diameter. What you need is radius, which is the measure of a circle from the middle of the circle to the outside, so it is half of a diameter. 

So to get radius (r), divide the base by 2. 
r = 10yd/2 = 5yd

Now that you have all that you need just input it into your formula:
L = r  x x l
   = 5 yd x  x 12.1 yd
   = 190.07 yd

So your answer is B.

We have that 
base=10 yd> r=5 yd
lateral area=pi*r*h--> pi*5*12.1=  190.07 yd²

the answer is option b. 190.07 yd2