Video Transcription
Or it only goes that far so that's the entire object distance minus this piece right over here
So if I subtracted this much from the object distance I'd get the remaining amount which is the adjacent part of this triangle
So this distance from the mirror to the focal point is given a name
It's called the focal length and we represent it with an F
So a little confusing because F represents both a point and it represents the length from the mirror to that point