How many different isosceles right triangles can be formed from three dots in the grid below? Two examples are shown.

Down below I think is the link to the triangle image

https://latex.artofproblemsolving.com/4/6/8/46880283129cd15b93da151b9df96e2514bfde69.png

Guest Jun 16, 2020

#1**+1 **

Tsk. The picture is hard to see, but I will try my best.

Isosceles triangles are triangles with 2 sides that are the same length. There are 9 dots.

There are triangles with side lengths 1, 1, sqrt(2) and 2, 2, 2*sqrt(2). So on and so forth. There are 16+4=20 triangles.

Yay!

Edit: I found that this question was posted 4 MONTHS AGO! Jesus... it's like you guys are doing the same course with the same questions or something...

Varxaax Jun 16, 2020