This post has been updated on 11 Jan 2023.
No matter where in the world you are or how you write the date, on July 24, 2025 is Pythagorean Theorem Day!
Pythagorean Theorem Day or Pythagoras’ Theorem Day is celebrated because the sum of the squares of the first two digits (7 and 24) is equal to the square of the year (25).
Now this doesn’t happen every year so it’s mathematically special.
August 15, 2017 (The previous Pythagorean Theorem Day)
8² + 15² = 17² OR 15² + 8² = 17²
July 24, 2025
7² + 24² = 25² OR 24² + 7² = 25²
Pythagorean Theorem Day also makes a great opportunity for teachers to engage students in learning activities related to geometry and mathematics.
First, have a review your students’ understanding of the Pythagorean Theorem and its components. How much of it do they know? What do they not know?
Once you’ve assessed their level of understanding, it’s time to get creative.
Give these Pythagorean Theorem themed activities a go!
1. Find the missing length
For younger students, create a giant triangle on poster paper in front of your class and write unknown side lengths on each corner.
Have students measure each side using rulers or measuring tape and then calculate the remaining sides using the theorem. This activity can be made more interactive by having students guess the answers before they measure them.
Think out of the box! Use fun visuals such as diagrams, images, and videos to make the learning more engaging.
For example, here’s how you can teach Pythagorean Theorem… using chocolate!
2. Who was Pythagoras?
Share his story with your students through a video or a book. Connecting well-known historical mathematics story like how how Pythagoras came up with his theory can inspire and help students relate to mathematics concepts in class.
Students can learn about Pythagoras in the Mathletics Dictionary, and what is he most well-known for.
3. Pythagoras Scavenger Hunt
Divide students into teams, and provide each team with a list of questions related to the theorem, such as: “What is the length of the hypotenuse if one of its sides is 3 and the other is 4?” or “Explain how to use the Pythagorean Theorem to find a missing side length.”
Once all questions are answered, award prizes to the winning team!
4. Build a “Pythagorean City”
Divide the class into small groups and have each group create a city block using cardboard or paper. Each group must include a building that incorporates the Pythagorean theorem (for example, a building with a triangular roof). Students can then give presentations on their city blocks, explaining how they used the theorem in their designs.
5. Pythagorean Theorem Mathletics sample activities
6. When is the next Pythagorean Theorem day?
Have your learners figure it out! Start by giving them the hint that Pythagorean Theorem Day will occur again in 2025.
You can provide the month to make it a little easier.
- July 24, 2025 (7/24/25 or 24/7/25): 7² + 24² = 25²
7. Connect it back to real life
Don’t forget to set aside time for students to reflect on what they have learned and discuss its application in everyday life scenarios. Some questions to spark their thinking:
- How do we use this equation in real world applications?
- What other types of equations are similar?
- How do these equations connect with each other?
With these discussions, it’ll give students an opportunity to reflect on their learning, and see how mathematics can be relevant to their everyday lives.
These are just a few ideas to get you started.
Feel free to adjust and adapt these activities to best suit the needs and interests of your students.
Most important of all… have fun!
