lines AB and CD intersect at point E. Ray EF is perpendicular to line AB. What is the measure of <CEF?

Line an and line CD are intersecting lines and they intersect at point e

None

What is the supplement of 80? *

To find the measure of ∠CEF, we need to gather more information about the problem.

Given that rays EF and AB are perpendicular, it indicates that angle ∠CEF is a right angle (90 degrees).

However, without additional information about the specific angles or lengths of the lines AB and CD, it is not possible to determine the measure of ∠CEF beyond being a right angle.

No idea. Could be anywhere from 0 to 180 degrees.

You haven't said which side of the line AB points C and F are, or anything about any other angles. All we know is that EF and AB are perpendicular. Point C could be anywhere except A or B.