This setup is similar to the previous triangle teaser we had earlier on this list. You have to find the missing mathematical instruction using the numbers on the side to reach the number in the middle. We are sure you got this- just think carefully!
However, pay attention. This one isn’t as simple as the previous one’s basic addition and subtraction. We want to challenge your further, which is why this one takes it up to the next level, so you really got to keep your wits about you. So without further ado, set those timers and give it a tri(-angle).