Petersen–Morley theorem

The Petersen-Morley theorem is a rule that helps us understand shapes and angles. Imagine you draw a big triangle and then connect the midpoints of each side, creating a smaller triangle inside. Then you connect the midpoints of the smaller triangle's sides, creating an even smaller triangle inside that one. You can continue doing this forever, creating an infinite number of smaller triangles each time. The Petersen-Morley theorem tells us that if you measure the angles inside the smallest triangle, they will always add up to exactly 180 degrees. This is a really important rule in geometry and helps us solve lots of problems!