How to Solve the “Triangle to Straight Line” Puzzle

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Learn the solution to this tricky riddle with our complete guide

Co-authored by Hunter Rising

Last Updated: December 6, 2025 Fact Checked

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Riddle

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Answer

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Why It’s Tricky

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More Riddles & Puzzles

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It seems simple: 3 sticks arranged in a triangle, and you just have to move one to make a straight line. If you’ve seen this viral brain teaser going around social media, it may leave you a little confused, but the answer is actually pretty easy with some creative thinking. Keep reading, and we’ll walk you through how to think through the solution and more riddles to try when you’re finished!

“Triangle to Straight Line” Riddle Answer Key

Triangle to Straight Line Answer Summary

To turn the triangle into a straight line, push the bottom stick up toward the top point of the triangle. The sticks on the sides will flatten out and turn into a straight line. Pick up the stick you were pushing and set it on top of the others.

Section 1 of 4:

What is the “triangle to straight line” riddle?

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You must change a triangle into a straight line using only 1 move. The riddle starts off with 3 toothpicks, pencils, or sticks arranged in a triangle. Your challenge is to move one of the sticks to transform the triangle into a single, straight line. Try it out for yourself a few times at first before jumping down to our answer.^{[1]
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- Hint: What are some different ways you can move the stick besides picking it up?
- Hint: You can only move one stick…but the stick you move can move the others.
- Hint: When an angle gets wider, it eventually flattens out into a line.

Section 2 of 4:

Triangle to Straight Line Solution

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Push the bottom stick up so the sides flatten into a line. Put your finger on the center of the bottom stick, or the base of the triangle. Push the stick up toward the point of the triangle. The ends of the bottom stick will push the side sticks into a wider angle until they eventually make a straight line.^{[2]
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- Push the stick slowly to ensure the side sticks stay lined up.
- After the side sticks flatten out into a line, pick up the stick you were pushing and set it on top.

Section 3 of 4:

Why is the “Triangle to Straight Line” puzzle tricky?

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When you think about moving a stick, you’d normally pick one up and place it somewhere else to make the right shape. If you only do that, you may think the puzzle is impossible and doesn’t have a solution. Solving the puzzle forces you to think of a different way to move a stick that might not be obvious at first.

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Similar Riddles and Puzzles

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Try these other puzzles with creative solutions to put your mind to the test. If you want even more brain teasers that make you think outside the box, we have a great collection for you to try out next! Take a few minutes on each riddle and see if you’re able to solve them on your own, but don’t be afraid to check the answers if you get stuck!