Bridget has a kitchen canister, in the shape of a cylinder, which holds flour. If the canister is 22 centimeters wide and 24 centimeters tall, what is its approximate surface area in terms of pi?
Answer
770π square centimeters
1,012π square centimeters
816π square centimeters
528π square centimeters

Question

Bridget has a kitchen canister, in the shape of a cylinder, which holds flour. If the canister is 22 centimeters wide and 24 centimeters tall, what is its approximate surface area in terms of pi?
Answer
		770π square centimeters
		1,012π square centimeters
		816π square centimeters
		528π square centimeters

anonymous · Answer

the trick here is to find the radius, since they gave you the diameter

anonymous · Answer

so would it be half of 22?

anonymous · Answer

the other trick is to get an exact answer (leave it in terms of pi)

anonymous · Answer

i did 3.14 x 11 = 34.54 i dont know where to go from here

anonymous · Answer

ok, what is the formula for surface area of a cylinder?

anonymous · Answer

2 π r2 + 2 π r h

anonymous · Answer

and they gave you the height

and the radius is 1/2 the diameter

so plug those in (leaving π in there as π) and simplify

anonymous · Answer

2 π r r + 2 π r h
2 π (11) (11) + 2 π (11) (24)

anonymous · Answer

2,417.8 is what i got ? not right

anonymous · Answer

what did you do to get that?

anonymous · Answer

i multiplied each side then added together

anonymous · Answer

dont multiply by 3.14
we want an exact answer here, leave π alone

anonymous · Answer

770?

anonymous · Answer

you got it!  exactly!

anonymous · Answer

thanks !