HELP: Geometry question related to home project.

[SplshMtn99]

LOL, a LONG time ago I was really good with this type of stuff. In high school, I was even advanced a year just in my math classes. Now, can't remember crap. (especially at 7am on Saturday -- yawn)

So, here's my question.

What size plywood circle do I need to cut/buy that will completely cover the top of a file cabinet that measures 18"x15"?

In other words, a 18x15 rectangle COMPLETELY fits into what size circle?

Thanks.

 

[Claire L]

You will need to work out the longest measurement which will be the diagonal from one corner to the other.

So 18 x 18 = 324, 15 x 15 = 225 added together = 549 and the square root of it is 23.4 so a diameter of 24 inches is needed.

I think I have read your post right??

Claire

 

[Mandabella]

You will need to work out the longest measurement which will be the diagonal from one corner to the other.

So 18 x 18 = 324, 15 x 15 = 225 added together = 549 and the square root of it is 23.4 so a diameter of 24 inches is needed.

I think I have read your post right??

Claire

I did the same thing and got the same anwer.

When you draw it, the diagonal from the rectangle is the the diameter of the circle. And just use a^2 + b^2 =c^2....it's never let me down.

 

[SplshMtn99]

yawn. I walked away, realized, duh, just measure ACROSS.

See, I'm an engineer's daughter. I was SURE a math formula & slide rule was absolutely necessary to figure this out.

Think I better go back to bed.

Thanks.

Oh, & you are right. My tape measure says 23.5". Much easier.

 

[Claire L]

Lol It does help that it has just gone midday here!

Claire

 

[SplshMtn99]

When you draw it, the diagonal from the rectangle is the the diameter of the circle. And just use a^2 + b^2 =c^2....it's never let me down.

YAWN THANKS, really!