Help pls i’ll give brainlest if it’s correct

Prove that quadrilateral is a rhombus.

Can someone me with this? i’m not sure what to put for my equations.

Apassenger train and a freight train leave san jose at 3pm, traveling in the same direction. the passenger train is going three times as fast as the freight train. at 6pm they are 240 miles apart. how fast is each travelling? explain your answer and show your