Question

@StudyGurl14
I hate to keep bugging you, but I just really need to get this chapter done. If you can go through the like 4 problems with me so I can practice, I would be so appreciative. I feel really stressed about not getting this. I want to learn, but I keep messing up.

Answer 1

Post your question, my friend. :)

Answer 2

Also, take a chill pill...stressing out about math makes you over-think it and makes it harder, when in reality it is pretty simple. Take some deep breaths, think positive thoughts, and power through.
I'll help you. :)

Answer 3

You are truly THE best! Thank you :) Okay so again I have to find surface area for a cylinder. I don't think we've done this one.

Answer 4

See I have a deadline when I have to turn this in so I'm just really stressed about that or else I think i'd be calmer.

Answer 5

Okay, so first you should find the lateral area. Then find the total area of the two circles and add that to the lateral area. Do you remember the formula for lateral area of a cylinder?

Answer 6

@lily1021

Answer 7

Lateral formula for cylinder was 2 * pi * r * h I think?

Answer 8

right

Answer 9

in this problem, 9 is the height, and 4 is the radius.

Answer 10

So 2 * pi * 4 * 9? Do we have to divide the 4by 2 since there's already a 2 in the formula?

Answer 11

no. no dividing. just simplify the expression^

Answer 12

Okay got it.

Answer 13

one quick question. are we expressing in pi form, or no?

Answer 14

yes

Answer 15

ok

Answer 16

then simplify everything except for the pi. so do 2*4*9 and tack on the pi at the end

Answer 17

72 pi

Answer 18

right

Answer 19

next step. find the area of one of the circles using the radius 4

Answer 20

pi * 4 ^ 2

Answer 21

pi * 16?

Answer 22

which is 50.26

Answer 23

leave pi as is. remember?
So you have 16pi
Since you have two identical circles, you have to multiply that by 2.

Answer 24

oh yeah I forgot that. I always want to multiply that for some reason sorry.

Answer 25

so my answer is 32 pi yd^ 2

Answer 26

right. add that to 72pi and you're done

Answer 27

104 pi yd^2

Answer 28

yep

Answer 29

so 13 + 4 + 12 = 29

Answer 30

not really @lily1021 . What do you mean by "add all the faces and then multiply by height"

Answer 31

so the 13 + 4 and 12? That's wrong then...

Answer 32

Do this:
\(\large (5\times12)+(4\times12)+(5\times4)+(4\times13)=the~answer\)

Answer 33

surface area is the total area of all the faces of a prism

Answer 34

so you find the area of each face and add them together to get the surface area

Answer 35

what would be the formula for that? like with letters so I know which ones to fill in?

Answer 36

the answers 180 then.

Answer 37

http://www.math.com/tables/geometry/surfareas.htm

Answer 38

and yes. 180cm^2 is correct

Answer 39

Is this just a regular prism or a rectangular prism?

Answer 40

this is a triangular prism i think

Answer 41

there really isn't a specific formula for it. You just have to know that you have to find the area of all the faces and add them together

Answer 42

make a net to help you.

Answer 43

Okay. So two more and I will leave you alone forever. I have to find again surface area for a prism. I think because all the shapes seem to be a little different here and there which is why I'm getting confused.

Answer 44

lol ok

Answer 45

okay, for this one there is a formula

Answer 46

okay

Answer 47

would this be a rectangular prism?

Answer 48

yep

Answer 49

so I do 2*8*13 + 2 first

Answer 50

is the base 8 or 13? I'm not sure?

Answer 51

Imagine that a = 8, b = 13, and c = 7

Answer 52

just plug into the formula and simplify

Answer 53

so 502

Answer 54

yep

Answer 55

you said I need to simplify that number or?

Answer 56

no that's the answer.

Answer 57

502

Answer 58

post your next question in a new thread please

Answer 59

Oh alright okay. So last one another surface area for the cylinder in terms of pi.

Answer 60

this one is getting long

Answer 61

Yeah I can't attach a picture anymore I'm going to start a new one okay?

Answer 62

ok