# An irrational puzzle

What's the answer to this puzzle?

• May I ask is the third symbol in the bottom line a triangle ($\triangle$) or capital delta ($\Delta$)? Also, is the fifth symbol a degree symbol or just a small 0? Thanks! Oct 4, 2022 at 8:10
• @CheeseCake Yes, it's a triangle Oct 4, 2022 at 8:13
• It's a degree symbol Oct 4, 2022 at 8:18

Prem's answer (+1) pretty much nailed it except that

the S.t. and picture with an X through it means such that it is not on the line connecting the red dots.

Then a

triangle with an angle more than 90 degrees is accomplished by any dot that is to the left of 1/4 or to the right of 3/4 or any dot within a circle of radius 1/4 centered on the center

So the

probability is 0.5 + 0.196 = 0.696

• Well done! This is the right interpretation and the answer is correct. Oct 6, 2022 at 7:37
• Nice [ +1 ] I agree that the "X" is "negation" , not "Diagonal Intersection" ! Observation : there is no Irrationality involved & the title was not a clue !
– Prem
Oct 6, 2022 at 8:22
• Why does the arrow for the yellow dot have some sort of flip indicator above it? Do we know what that means?
– Amoz
Oct 6, 2022 at 12:46
• @Prem the rot13(nern bs gur pvepyr / cv) is irrational Oct 6, 2022 at 17:47
• @Amoz good question, i dunno. that is actually where I got stuck the first time i looked at this puzzle Oct 6, 2022 at 17:47

What I got till now :

Take 2 red Dots or Points. Put those into the Square.

Each Dot must be 1/4 Distance from the vertical sides.

Each Dot must be 1/2 Distance from the top side.

Take a yellow Dot & put it into the Square.

Such that , It is on the line joining the 2 red Dots where the Diagonal lines are shown to intersect this line at the Centre.

What is the Probability that the Angle in the triangle is more than 90 ?

Might be Irrational , involving PI or trigonometry.

• Good job (+1), you had the right idea except for the lower part of the puzzle. A correct answer has been given by Cap Oct 6, 2022 at 7:34
• Oh ok , (1) I thought that It was the Diagonal Intersection , not a negation (2) I thought that there must be Irrational Probability. Either ways, Nice Puzzle !
– Prem
Oct 6, 2022 at 8:17