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View Full Version : Simplest math problem of today



slackeru
02-12-2014, 12:30 PM
I haven't had math in school for about 3 years, and I suck at it.
I have 3 circles, each with 100mm diameter, which makes the radius 50mm. I want the area of those 3 circles together.
I did
50mm * 50mm * Pi = 7854mm^2
7854mm^2 * 3 = 23562mm^2

Then I tried doing
50mm * 3 = 150mm
150mm * 150mm * Pi = 70685mm^2

Which one is it? I think it's the first one, but why is the second one so different?

onilika
02-12-2014, 01:03 PM
You want the area of those 3 circles togetther? I don't get it.
like ooo ?

slackeru
02-12-2014, 01:23 PM
You want the area of those 3 circles togetther? I don't get it.
like ooo ?

I'm making a square wooden plank with the same area that those 3 cicles would've produced

onilika
02-12-2014, 02:13 PM
I would calculate the area of a circle, and then multiply by 3..
so.. Pi * (radius^2) = 7850 mm^2

Circles area = 7850 * 3 = 23550 mm^2

So, a square wooden plank with 23550 mm^2.

That's how I would make

The second you did, you are saying that the radius of the circle is 150mm. But you have 3 circles, each one with 50mm. So the first is the right method.
That's how I would make it :)

Cheers!

Solar
02-12-2014, 02:27 PM
Three non intersecting circle (not overlapping) would give the first solution you typed.

slackeru
02-12-2014, 03:17 PM
Thanks!