Question

reviewing undefinable terms
the intersection of plane r and plane p is line db
point is not on plane p.
ce and db intersect at point

Explanation:

Step1: Identify points not on plane P

By observing the figure, point H is clearly outside plane P.

Step2: Find intersection of lines

Lines $\overleftrightarrow{CE}$ and $\overleftrightarrow{DB}$ intersect at point D as seen from the figure.

Answer:

Point H is not on plane P. $\overleftrightarrow{CE}$ and $\overleftrightarrow{DB}$ intersect at point D.