anonymous one year ago A cylinder has a volume of 175pi cubic units and a height of 7 units. The diameter of the cylinder is 5 units 10 units 12.5 units HELP!!!!!!!!! Because I don't understand this at ALL!!!!!!!

1. Jack1

Volume of a cylinder = pi x r^2 x h

2. Jack1

a diameter is twice the radius... so diameter is 2 x r $$\Large V = \pi \times r^2 \times h$$ V = 175pi h = 7 pi =3.1415.... now solve for r then double it

3. anonymous

So would you divide everything over the the 175?

4. Jack1

$$\Large V=π×r^2×h$$ $$\Large 175\pi=π×r^2×7$$ so first... divide both sides by pi then divide both sides by 7 then you should be left with r^2 = ... a number then sqrt both sides and you should be left with r then double it... and that = d

5. anonymous

I just got a number like 4,000 and something. I seriously don't understand :( I'm sorry...

6. anonymous

OOOH WAIT!

7. anonymous

8. Jack1

bam! u rock!

9. Jack1

yep, d = 10 ;)

10. anonymous

Thank you so much! Sorry it took so long lol

11. Jack1

all good dude, if it was easy it wouldn't be fun ;)