Question

Find the surface area of a sphere with a diameter of 15 inches. Use 3.14 to approximate π. Round answers to the nearest hundredth.
a)
706.5

b)
2,122.64

c)
1,297.67

d)
460.32

Answer 1

well do you know the formula for the surface area of a sphere?

Answer 2

no

Answer 3

\[SA=4\pi r ^{2}\]

Answer 4

ok so how do I find the answer

Answer 5

well plug it in to the equation
first what's half of 15

Answer 6

7.5

Answer 7

don't forget that we're dealing with radius. don't put in the diameter.

Answer 8

ok

Answer 9

right so given what you have what does the equation look like, don't solve it yet, but write it out.

Answer 10

15* 3.14

Answer 11

is that right

Answer 12

not exactly, what is 7.5^2, you might need a calculator.

Answer 13

15

Answer 14

no you're squaring 7.5 not multiplying by 2.
7.5 times 7.5

Answer 15

56.25

Answer 16

exactly, so without multiplying any thing what does the equation look like?

Answer 17

idk

Answer 18

56.25*3.14

Answer 19

close remember it's
4 times pi

Answer 20

12.56

Answer 21

great so what is the net step

Answer 22

12.56*3.14

Answer 23

if that's not it then idk

Answer 24

well remember 4 times pi so wouldn't you have 12.56 times 56.25

Answer 25

well I tried that but I didn't get any of the right answers

Answer 26

i did that and i got 706.1232

Answer 27

ok let's break it down, we have
(4 times pi) times (7.5 squared)

Answer 28

706.5

Answer 29

yes do you understand how to get there?

Answer 30

no not really

Answer 31

let's break it down, we have
(4 times pi) times (7.5 squared)
let's look at the left parentheses first.

Answer 32

ok

Answer 33

ok so its 4 * 3.14

Answer 34

right so what does that equal

Answer 35

12.56

Answer 36

correct now set that aside, let's look at the right parentheses.

Answer 37

56.25

Answer 38

right so now what does the equation look like with those two numbers, 56.25, and 12.56

Answer 39

56.25*12.56

Answer 40

right so what does that equal

Answer 41

706.5

Answer 42

yep great job

Answer 43

that's not one of my at one of my answers

Answer 44

o wait it is sorry looking at the wrong question

Answer 45

no problem, great job

Answer 46

thank you tahnxs for the help

Answer 47

any time.

Answer 48

can you help me with another 1

Answer 49

im trying to do it exactly like the way you just showed me but im not getting the right answer