Hi, happy 2023 ^^

Maybe a math-based game can interest a few here?

You can post any math-related quiz (eg simple geometry, critical thinking etc - obviously NOT homework-type ) and whoever answers correctly, first, can post the next challenge...

Here is a relatively simple one (just involves basic geometry), I hope some will participate and upon solving it post the next:

To win, just calculate (using any method) the value of x. "O" is the center of a circle=>center of the diameter AB.