Question

find the surface of a sphere with diameter of 15 inches.use 3.14 to approximate pie. rounded answers to the nearest hundreth.

Answer 1

Area of a circle is equal to:

\[\ 3.14 r^2\]

Where r is the radius of the circle.

The radius of a circle is half the diametre. Does this help?

Answer 2

yes , so since i cant take half of 15 i get the square root of 15?

Answer 3

Half of 15 is 7.5

Answer 4

used the first equation and i put r=1/2

Answer 5

and i got 0.785

Answer 6

r does not equal .5. r is one half of d.
Since the diameter = 15 and the radius = .5diameter, r = 7.5

Answer 7

so i plug in using the first equation 3.14(7.5)^2

Answer 8

i did that and thats not any of my answer choices

Answer 9

@chaise posted the area of a circle, not a sphere. The surface area of a sphere is \[4\pi r ^{3}\]. Use that.

Answer 10

i got 5298.75
but my answer choices are :
a: 706.5
b: 2122.64
c: 1297.67
d: 460.32

Answer 11

It's 706.5. I copied the equation wrong. It's:
\[4pir ^{2}\]

Answer 12

ohhh . . i see thanks for your help . Are you good with Absolute Value Functions?

Answer 13

Used to be good with all of it, just been a while :) Gotta look stuff up on Google / Wikipedia to remember it lol

Answer 14

lol ook . I wondering can you help me your good at explaining stuff .

Answer 15

Post a new question and I'll see what I can do.

Answer 16

kk thankss