“No, that wouldn’t have happened. That’s where the Pythagorean Theorem comes in.”

“What’s that?”

“You should have learned this in middle school. With any right-angled triangle, the area of the square whose side is the hypotenuse is equal to the sum of the areas of the squares of the other two sides.”

“Huh?” Muraki said, so Hashimoto took out his notebook and drew a picture. He drew a

right triangle, and three squares that bordered the edges of the triangle.

“Like this?”

“Yes,” Kiyoshi said.

“The sum of the squares of the two smaller sides is equal to the square of the large one.”

“Is that possible with a triangle of any size?”

“If it’s a right triangle, definitely.”

“This is very interesting,” said Hashimoto.

“It’s a very old theorem developed by the ancient Greeks. A mathematician named Pythagoras discovered this,” Kiyoshi said.

“Amazing.”

“This house is built using the Pythagorean concept. The sum of the areas of the two studios upstairs is equal to the area of the guest room downstairs.”