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21-Topaz I
21-Topaz I
March 23, 2024
Solved

Find the length AB.

  • March 23, 2024
  • 5 replies
  • 5666 views

Elementary schoole children can solve this puzzle. If you need you can use Mathcad Prime.

image.png

Best answer by terryhendicott

Capture.jpg

5 replies

15-Moonstone
March 23, 2024

There are two intermediate solutions. In the end AB=11 in any case 😉

21-Topaz II
March 23, 2024
ttokoro
21-Topaz I
ttokoro21-Topaz IAuthor
21-Topaz I
March 24, 2024

If we use Mathcad it is easy to find the answer. But without sqrt or functions, this puzzle becomes very hard. 

 

image.pngimage.pngimage.png

t.t.
15-Moonstone
March 24, 2024

This task is not particularly difficult. Students should be able to solve it using the cosine law for side length and the sine formula for the area of a triangle. What is much more interesting about this problem is that solution "11" is possible in two different geometric situations.

21-Topaz II
March 24, 2024

Hi,

Prime 9 Express version:

Capture.JPG

Cheers

Terry

15-Moonstone
April 1, 2024

Additional task: 😉

Given pieces and requirements as usual.

But:

Instead of the given area F=60, the distance AC must now be calculated so that the area of the triangle ABC is maximum. How big is the interior angle at C?

15-Moonstone
April 2, 2024

Correction:
With the unusual names of the triangle vertices as shown in the sketch in the original problem, the distance AB is logically sought. I accidentally had the usual point designation in my head, where A and B limit the lower side of the triangle and C is the summit.

25-Diamond I
April 5, 2024

I would solve it that way:

Werner_E_0-1712277132704.png

 

Using Mathcads solving and plotting facilities it may look like this:

Werner_E_0-1712278501328.png

 

Mathcad 15 sheet attached