Can someone help me?
If a sphere has a diameter of 26 units then what is the surface area of the sphere?
A.) 507 π square units
B.)1,352 π square units
C.)2,929 π square units
D.) 676 π sqaure units

Question

Can someone help me?
If a sphere has a diameter of 26 units then what is the surface area of the sphere?
A.) 507 π square units 
B.)1,352 π  square units
C.)2,929 π square units
D.) 676 π sqaure units

anonymous · Answer

$$A = 4 \pi r^2 = 4 \pi 13^2 = 676 \pi$$

anonymous · Answer

You just posted this.. Don't repost.

anonymous · Answer

Did you find the surface area equation?

anonymous · Answer

@ muh4ha thanks so much :)

anonymous · Answer

no problem katie - but you rly should try and understand it, so you can do it on your own. Did you get, why I plugged in 13 ?

anonymous · Answer

ni can you explain?

anonymous · Answer

Because the 'r' in the Formula is the 'radius' of the sphere - that's the distance from the center to the surface. You are given the diameter - that's twice as much (same as when looking at a circle)..

So another way of writing the formula would be:
$$A = 4 \pi ({d \over 2})^2$$
okay? Did you get it?

Any other questions?

anonymous · Answer

oh wow thanks so much :)

anonymous · Answer

you're welcome :)

best thing to do, would be to try another example completely on your own and see if you can get it ;)