help me with that and graph

A cyclist leaves her house at 8:00AM and begins travelling directly east at 20 km/h. Fif- teen minutes later, her friend, who lives 2 km directly south, gets in his car and begins to travel directly west at 50 km/ h. Find the rate at which the distance between the cyclist and the driver is changing at 8:30AM. Sketch a diagram, and be sure to Show all work leading to your solution. Work that is incomplete, messy, or otherwise incoherent will deductions