Question

What is the surface area of a conical grain storage tank that has a height of 37 meters and a diameter of 16 meters? Round the answer to the nearest square meter.

A. 2,831 square meters
B. 2,664 square meters
C. 1,152 square meters
D. 1,131 square meters

Answer 1

@TheSmartOne

Answer 2

To find the surface area of a cylinder you have to use this formula....
\[SA=2 \pi r h + 2 \pi r^2\]

Answer 3

so how do we get the radius?

Answer 4

I'm not sure about the radius. @563blackghost

Answer 5

Can you help me figure it out?

Answer 6

To find the radius but given the diameter we need to divide the diameter by 2....\[16 \div 2 =?\]

Answer 7

8

Answer 8

I looked up diameter and it said that it is twice the length of the radius, so I went a did that math and actually got 8, but wanted to make sure I was right.

Answer 9

Yup that's correct! So now we need to input the numbers we know...\[SA=2(3.14)8(37) + 2(3.14)8^2\]

Answer 10

I got 1,858.88+401.92 which equals 2,260.8

Answer 11

So, would my answer be 2,664? Because that is the closest to the answer I got.

Answer 12

Yup the answer is B...

Answer 13

Thanks! Could you help me out with another question?

Answer 14

Sure!

Answer 15

I had to post the screenshot because I couldn't type it out.

Answer 16

thats alright

Answer 17

By the way I really appreciate your help. I'm just so behind in school, my grandfather passed away last week and it's just been hard.

Answer 18

Ooo I'm so sorry to hear that :( , im glad I can help though....

Answer 19

To find the Surface Area of a Rectangular Prism you need to use this formula...\[SA=2(wl+hl+hw)\]

Answer 20

So, what I'm confused about is which one is the width, length, and height?

Answer 21

Everyone gets confused with that :P ....

l = 17
w = 5
h = 3.12

Answer 22

So, 144.88?

Answer 23

hmmm...not quite..\[SA = 2(85+53.04+15.6)\]

Answer 24

How did you get those numbers?

Answer 25

But I got 307.28.

Answer 26

Thats correct! The Surface area is 307.28cm^2

Answer 27

Now we need to find the lateral area...

Answer 28

And we'd do that by multiplying the perimeter by the height?

Answer 29

@563blackghost

Answer 30

Yup we have to multply the perimeter of base by the height...

Answer 31

So, how'd we do that?

Answer 32

\[LA= (17+17+5+5)3.12\]

Answer 33

137.28! So the answer would be C?

Answer 34

I hate to ask, but could you help me out with just one more question? @563blackghost

Answer 35

Yup the answer is C! I can help with one more ;)

Answer 36

Lets first find the lateral area.... \[LA=(a+b+c)h\]
A = 9
B = 3
C = 9.49
H = 37

Answer 37

795.13

Answer 38

Correct so the lateral area is 795 cm and we can cross off B and D....

Answer 39

So, now for the surface area?

Answer 40

Now we need to find the surface area...\[SA=wh+lw+lh+ls\]
l = 37
w = 9
s = 9.49
h = 3

Answer 41

822.13

Answer 42

Correct so the answer is C !!! xD

Answer 43

I found another question on my lesson that is like the same thing but i'm not familiar with it.

Answer 44

I can look at the problem for you...

Answer 45

Lets first find the surface area...\[SA= \pi r^2 + \pi r l\] we will use this formula...

Answer 46

\[So, 3.14*12^2+3.14*12*21?\]

Answer 47

Yup!

Answer 48

I got 1,243.44.

Answer 49

But rounded it's about 1,244.1.

Answer 50

Correct! so we can cross off A and C... Now we need to find the lateral area of the cone...

Answer 51

We will use this formula to find Lateral Area...\[LA= \pi r l\]

Answer 52

\[3.14*12*21=791.28\]

Answer 53

Yup so we can round it off the 791.7 so the answer is D!!

Answer 54

Can I ask for help on one more question? I seriously promise this is the last.

Answer 55

Ok!

Answer 56

The formula for a hexagonal pyramid is ...\[SA=3ab+3bs\]

Answer 57

this one is a bit harder for me...

Answer 58

So, what numbers would be plugged in for a, b, and s? And I don't mind, I appreciate the help a lot.

Answer 59

S = 9
b = 13
a = 6.5 sqt 3

Answer 60

What is the answer to 6.5 sqt 3?

Answer 61

It says 11.25.

Answer 62

\[6.5\sqrt{3} = 11.25833025...\]

Answer 63

I got 789.75. I assume by rounding the answer is going to be 790 and that means the answer is D.

Answer 64

Correct! :D

Answer 65

By the way, do you know what the formula is for finding the volume of a cylinder?

Answer 66

\[V = \pi r^2 h\]

Answer 67

Oops, I figured it out.(:

Answer 68

:P

Answer 69

Do you know how I'd solve this one?

Answer 70

hmmm...find the volume of the two prisms and add each volume together..

Answer 71

So, I know we've been going over lateral and surface area, but I'm confused as on how to solve this. Is there a formula I can use?

Answer 72

To find the lateral area for a cone you use...\[LA= \pi r l\]

Answer 73

Which one is the radius in this problem?

Answer 74

Well in the problem you are given the diameter and in order to find the radius you have to divide the diameter by 2...

Answer 75

soooo 60/2...

Answer 76

30.

Answer 77

yup!

Answer 78

I am sorry but I need to go...

Answer 79

So, 3.14*30*40?

Answer 80

Yup! xD

Answer 81

Would it be B?

Answer 82

Yup! xD

Answer 83

Thank you so much!

Answer 84

Np ;) I am so happy I was helpful ..bye