Welcome to the CPL HPL question and answer forum. Please feel free to post your questions but more importantly also suggest answers for your forum colleagues. Bob himself or one of the other tutors will get to your question as soon as we can.
Pregs created the topic: downslope runway
how does a downslope runway make a pilot do a steeper approach than normal?
It's all a matter of perspective. The approach to a down-sloping runway gives the impression that the approach angle is shallower (the aircraft is too low.) That's because the angle perceived is the angle between the approach path and the runway surface (red) rather than the horizontal (yellow). See the figure.
The pilot is likely to compensate by flying a higher and steeper approach than necessary.