4 yd
What is the diameter?

4

Step-by-step explanation:

   circumference: 12.56 yd

   area: 12.56 yd²

Step-by-step explanation:

The formula for circumference is ...

 C = πd

 C = (3.14)(4 yd) = 12.56 yd . . . . . . . . fill in the numbers; do the arithmetic

The circumference is 12.56 yd.

__

Since the diameter is 4 yd, the radius is half that, or 2 yd. The formula for the area is ...

 A = πr²

Fill in the numbers and do the arithmetic.

 A = (3.14)(2 yd)² = 12.56 yd²

The area is 12.56 yd².

Comment on units

In problems such as these, I find it is often useful to keep the units with the numbers. The units can be treated like any variable: multiplied, divided, measures combined by addition or subtraction of "like units".

Just as (2a)² = 2²·a² = 4a², so does (2 yd)² = 2²·yd² = 4 yd². You can be sure that if the units of the problem don't make sense, there is an error somewhere.

answerim :

n

step-by-step explanation:

im not sure but my dad knows

your answer   is c

step-by-step explanation: