Find the interior angle on a regular polygon with 45 sides...

The exterior angles sum to 360º. Let x be the measure of each exterior angle. Then

45x = 360º  ==>  x = 8º

Then each interior angle (which is supplementary to an exterior angle) has measure (180 - x)º, so they have measure 172º.

what is the question? i am guessing you are looking for the area.

to find an area, you have to do length x width.

in this case, it would be 12 ft x 4 ft = 48 sq. ft