Paddleducks

General => Chat & Off Topic Stuff => Topic started by: Eddy Matthews on March 17, 2007, 08:23:49 PM

Title: Puzzle
Post by: Eddy Matthews on March 17, 2007, 08:23:49 PM
Okay, all you mathematical geniuses out there.... Explain this one, it's driving me nuts!
Title: Puzzle
Post by: Roderick Smith on March 17, 2007, 09:36:17 PM
The master shape isn't a triangle.
The dark green has a slope of 2/5 = 0.4
The red shape has a slope of 3/8 = 0.375.
In the top arrangement, the shapes are concave compared to a pure 5x 13 triangle.
In the lower arrangement, the shapes are convex compared to a pure 5x13 triangle.
The difference adds up to 1 unit.

A 5x13 has an area of (5x13)/2 = 32.5
The four areas are:
Red: (3x8)/2 =12
dark green (2x5)/2 = 5
orange = 7
light green = 8
total: 32

In the top, they are arranged 0.5 short of the illusion; in the bottom they are arranged 0.5 above the illusion.

Regards,
Roderick B Smith
Rail News Victoria Editor
Title: Puzzle
Post by: Eddy Matthews on March 17, 2007, 10:00:51 PM
So basically it's an optical illusion, and the answer was staring me in the face all the time - Literally!

Thanks Roderick, I knew there had to be a solution! :)
Title: Puzzle
Post by: derekwarner_decoy on March 17, 2007, 10:16:24 PM
OK.... it had me stumped with

red= 5X2 divided by 2=....... :rant ....& the sum  of....=  :shock:  :?:  :idea:  :arrow: = 32 again & again  :shoot

thank goodness it was an OZ  :respect2 member who resolved the question.....on ya Roderick..... :beer .....Derek... I will now go back to bending bits of 5/32" brass tube   :hammer  :hammer
Title: Complex maths
Post by: Roderick Smith on March 17, 2007, 10:26:01 PM
A vaguely marine joke heard on Darwin radio news:
For our friends in the airforce, the time is 15.00
For our friends in the navy, the time is 3 pm
For our friends in the army, the big hand is on the 12 and the little hand...

Regards,
Roderick B Smith
Rail News Victoria Editor
Title: Puzzle
Post by: derekwarner_decoy on March 18, 2007, 01:11:06 AM
Hi PD's - outside of our WEBsite, my CA [Computer Associates] Internet Security Suite 2007 canned  :crash the posting>>>>> possibly as being  :offtopic.... :sorry ....not sure how these computer people  :computer  understand word structures & the like  :?:  :arrow: or am I missing something?................Derek