1. The problem statement, all variables and given/known data if displacement is the shortest distance between two point then that would also meant that it is equivalent to the hypotenuse when using phytogaras theorem right?. but why isnt displacement the shortest length between two point ?because Xinitial - Xfinal couldnt posibly be the displacement (shortest distance between two point is from phytogaras theorem. where Xi^2 + Xf^2=displacement^2) this is soo confusing. please help 2. Relevant equations pythagoras theorem states that the length of hypotenus^2(a.k.a shortest distance between two position) is equal to the length of (opposite^2)+ (adjacent^2). but in physic the displacement is not equal to the length of the hypotenus why is? this so contrary to a lot of books stating that displacement is the shortest distance between two position. 3. The attempt at a solution this is just an understanding problem . i understand 100% the difference between distance and displacement . i just got confuse why some book define displacement as the shortest distance between two position or points in a straight line. But Pythagoras would said NO that is not true as that would be the hypotenuse . who is right ?physicist or pythagoras? or am i totally got the wrong idea all together? if car 400m at time 0sec moves in a straight line and stop 1000m at time 5sec. if we plot this in Cartesian plane then to get the velocity we do rise over run which is the slope of the line. rise over run also means that it can be obtained from forming a triangle this also means that phytagoras theorem should be valid. but why ?this is soo confusing i dont understand . is hypotenus not equivalent to the magnitude of change in position? why is the change in position is the final minus initial ( which makes a lot of sense) but i am confuse. i dont even know how to phase my question correctly due to my bad english vocab grammar etc.