How Many Triangles?

MCSH wrote: 56... and can prove it:D

Alexandre Orion wrote:

MCSH wrote: 56... and can prove it:D

THAT'S OUR SAJJAD !!!!!

... now, please show us.

Count those that have the bottom edge and the 2 other edges are equal (4)
Now we'll count those on left side and then multiply it by 2, (to cover those on right as well)
To count those on left, you can count those that their right edge is lowest line that comes from right, and then multiply it by 4.
They are:
3 small ones + 2 made of two small triangle + 1 made of 3 triangles + 3 that have bottom line (9)

Weird... it results in 76... I should've made a mistake in calculation last time

Adhara wrote: I got 8 or 80, depending on what you count as a triangle
But I may have missed some...

MCSH wrote:

Alexandre Orion wrote:

MCSH wrote: 56... and can prove it:D

THAT'S OUR SAJJAD !!!!!

... now, please show us.

Count those that have the bottom edge and the 2 other edges are equal (4)
Now we'll count those on left side and then multiply it by 2, (to cover those on right as well)
To count those on left, you can count those that their right edge is lowest line that comes from right, and then multiply it by 4.
They are:
3 small ones + 2 made of two small triangle + 1 made of 3 triangles + 3 that have bottom line (9)

Weird... it results in 76... I should've made a mistake in calculation last time

Warning: Spoiler!

Only focusing on one side for a second:

Taking the line from bottomright to bottomleft, the lowest line on the left goes across to meet the line bottomright<->top. Using the lines that leave the bottomright point you can make 4 triangles that use that point.
Taking the point that intersects the lowest line from bottomright with the lowest line bottomleft, you can use the other lines bottomright<->top to make 3 triangles that use that point. (remembering that it is one less because there is one fewer line (the bottom one) being used)
Follow this for the other two points that intersect with the lowest line from bottomleft and you can make 2 triangles and then 1 triangle.

4+3+2+1=10

That can be done with each of the (4) lines leaving bottomleft point so you have 4x10=40 and that can be doubled by mirroring it on the other side so 2x40=80

At least I think that's right

Akkarin wrote:

MCSH wrote:

Alexandre Orion wrote:

MCSH wrote: 56... and can prove it:D

THAT'S OUR SAJJAD !!!!!

... now, please show us.

Count those that have the bottom edge and the 2 other edges are equal (4)
Now we'll count those on left side and then multiply it by 2, (to cover those on right as well)
To count those on left, you can count those that their right edge is lowest line that comes from right, and then multiply it by 4.
They are:
3 small ones + 2 made of two small triangle + 1 made of 3 triangles + 3 that have bottom line (9)

Weird... it results in 76... I should've made a mistake in calculation last time

My solution:

Warning: Spoiler!

Only focusing on one side for a second:

Taking the line from bottomright to bottomleft, the lowest line on the left goes across to meet the line bottomright<->top. Using the lines that leave the bottomright point you can make 4 triangles that use that point.
Taking the point that intersects the lowest line from bottomright with the lowest line bottomleft, you can use the other lines bottomright<->top to make 3 triangles that use that point. (remembering that it is one less because there is one fewer line (the bottom one) being used)
Follow this for the other two points that intersect with the lowest line from bottomleft and you can make 2 triangles and then 1 triangle.

4+3+2+1=10

That can be done with each of the (4) lines leaving bottomleft point so you have 4x10=40 and that can be doubled by mirroring it on the other side so 2x40=80

At least I think that's right

You are counting those at center twice so it's 4 more