1. Problem: Explain what the "trojkat egipski" (Egyptian triangle) is. 2. The Egyptian triangle is a right triangle with side lengths in the ratio 3:4:5. 3. This means if one side is 3 units, the next is 4 units, and the hypotenuse is 5 units. 4. This triangle is important because it is a simple example of the Pythagorean theorem, which states that in a right triangle: $$a^2 + b^2 = c^2$$ where $a$ and $b$ are the legs and $c$ is the hypotenuse. 5. For the Egyptian triangle: $$3^2 + 4^2 = 9 + 16 = 25 = 5^2$$ which confirms it is a right triangle. 6. This triangle was used by ancient Egyptians for construction and land measurement because of its simple integer side lengths. 7. In summary, the "trojkat egipski" is a right triangle with sides 3, 4, and 5 units, demonstrating the Pythagorean theorem in a simple way.