Calling all brainteaser lovers: this triangle puzzle (and no, it’s not an optical illusion) is sure to baffle even the sharpest brain for a few minutes. Kumar Ankit, an engineering student from India, designed and posted this geometric puzzle on Quora, challenging users to find all the hidden triangles in this image. You’ll really have to exercise that eye for detail (and a thorough concept of geometry) to solve this visual riddle. How many triangles do you see?