00:01
I'm going to find the surface area of this sphere.
00:05
I drew it because you always want to draw whatever you have when you're doing any kind of geometry problem.
00:13
And so i drew the sphere given the parameters that i had, which were that it was a sphere, and that it has a radius of two inches.
00:22
And the second thing that you always do is write the formula that you're going to use.
00:26
So we're finding surface area.
00:27
So i wrote the surface area of a sphere formula, which is 4 pi r squared.
00:32
Now i have to figure out what the value is that i'm going to use.
00:36
So i need the radius and it just so happens that i have been given the radius value.
00:41
So i'm going to write down the value that i was given, which is two inches.
00:46
And now i'm going to substitute that into my formula.
00:49
And so i instead of r squared, i'm going to have my radius, which is two.
00:54
Now all i have to do is solve.
00:57
And so i have the surface area of my sphere.
01:00
Is 4 pi 2 squared 4 pi oh and they want this rounded to the hundreds that's come gonna come in handy later and so 2 squared is 4 and then i'm gonna do 4 i'm gonna use the commutative property here and do 4 times 4 times pi and 4 times 4 is 16 so i have 16 pie.
01:31
Now, because they want it in a round it to hundreds, i'm actually going to approximate pie to 3 .14, and i get 27...