+0  
 
+4
544
8
avatar+91225 

 

I think it is time for us to have a new puzzle thread   laugh

THIS THREAD WILL BE AVAILABLE IN THE STICKY TOPICS

 

-----------------

 

There are lots of good puzzles in this maths is fun site. 

 

"Samuel Loyd (January 31, 1841 - April 10, 1911), perhaps Americas greatest ever puzzle maker, invented and refined thousands of puzzles in his lifetime. Word puzzles, rebuses, tangrams and math puzzles. Here we have collected some of his best math puzzles from his Cyclopedia of Puzzles for your enjoyment." (Mathsisfun)

 

https://www.mathsisfun.com/puzzles/sam-loyd-puzzles-index.html

SAM  LOYD PUZZLES

 

CPhill introduced me to Sam Loyd puzzles here:   Thanks Chris  laugh

https://web2.0calc.com/questions/how-much-do-they-weigh

 

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Here is an old puzzled threads  (December 2015)

https://web2.0calc.com/questions/puzzles_2

Melody  Sep 24, 2017
edited by Melody  Sep 24, 2017
Sort: 

8+0 Answers

 #1
avatar+1493 
+2

Here's one to begin the thread! 

 

The leg of a right triangle is \(\frac{1}{3}\) the sum of the other sides, and the perimeter is 12 units. What is the area of this traingle?

 

Good luck to any participants!

TheXSquaredFactor  Sep 24, 2017
 #3
avatar+91225 
+1

Thanks XSquared   laugh

 

Chris has already answered and that is great but I have a suggestion.

 

How about people answer on a new question thread and then put in an answer link.

That way the answer is not right with the question. It is more like having to look up the back of the book for the answer.

 

This might not work for a lot of people and that is fine, it is just a suggestion   laugh

Melody  Sep 24, 2017
edited by Melody  Sep 24, 2017
edited by Melody  Sep 24, 2017
 #5
avatar+1493 
+1

Sounds good to me! 

TheXSquaredFactor  Sep 24, 2017
 #2
avatar+79794 
+3

The leg of a right triangle is 1/3  the sum of the other sides, and the perimeter is 12 units. What is the area of this traingle?

 

Let a, b  be the legs and c the hypotenuse

 

So

 

a^2 + b^2  =  c^2   ⇒     a^2 = c^2  - b^2 ⇒   a  = sqrt ( c^2 - b^2 )

 

3a  = b + c

 

a + [b + c]  = 12

 

a + 3a  =  12

 

4a  = 12

 

a  = 3

 

This implies that    c^2 - b^2  =  9

 

And b + c = 9 

 

So

 

c^2 - b^2 =  b + c

(c - b) (c + b) =   (b + c)     divide through by  (b + c)

 

So 

 

(c - b)  =  1  ⇒   c = b + 1

 

So

 

b + ( b + 1)  = 9

2b = 8

b = 4        and c  = 5

 

And the area is just the  product of the legs / 2   =   a * b / 2 =  3 * 4 / 2  =  6 units^2

 

 

 

cool cool cool

CPhill  Sep 24, 2017
 #4
avatar+1493 
+2

Correctamundo! 

TheXSquaredFactor  Sep 24, 2017
 #6
avatar+5552 
+1
hectictar  Oct 2, 2017
 #7
avatar+91225 
0

 

Here is 2 area puzzles.    Have fun :) 

 

https://web2.0calc.com/questions/area-puzzles

Melody  Oct 4, 2017
 #8
avatar+91225 
+1

How old are the children ??

Solved by the distinguished super sleuth Ginger !!

 

https://web2.0calc.com/questions/jeg-vil-ha-svar-fort

Melody  Oct 10, 2017

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