I think the answers are A and B, but I would appreciate it if you helped me out.

Question

nevermind_justschool · Answer

attachment

ribhu · Answer

b&C

nnesha · Answer

|dw:1424554562825:dw|
like i told your diameter is from one side of circle to the other side right

nevermind_justschool · Answer

Yeah, you did

nnesha · Answer

|dw:1424554594992:dw|
radius is half of diameter 
so first you have to divide by 2

nevermind_justschool · Answer

So B. and C. like ribhu said.

nnesha · Answer

for answer choice C 
diameter is 20 divide by 2  then u get 10 which is radius 
so $$\huge\rm C= 2 \pi r$$
 replace r by 10 then solve

nnesha · Answer

why A is wrong :
they gave u the diameter which is 40 divide  by 2  to get radius 
40 / 2 = 20 
now replace r by 20   C= 2 pi r 
and then solve 
let me know what you get

nevermind_justschool · Answer

125.6

nnesha · Answer

$$\huge\rm C = 2 \pi r$$
just replace r by 20
don't use pi 
just 2 times 20 
bec in the question they gave u 20 PI

nevermind_justschool · Answer

Okay, that makes sense. Thank you. :)

nnesha · Answer

np 
2 times 20 is not equal to 20 so A is wrong :)