Construct a perpendicular line to CD from P
draw a line that goes through p and intjersects CD at a right angle.
this is what perpendicular means.
HOPE THIS HELPED!
intersects is basically where you have two linse that cross.
for example, two lines that do not cross do not intersect, but two that do cross intersect.
in this case, you would need to linse that intersect at a right angle.
basically you could just draw two lines on top of each other and then turn one a quarter of a circle, because a full circle is 360 degrees and 90 degrees (or a right angle) is 1/4 of that.
it would look like this: