Answer:
-x^7
Step-by-step explanation:
If x is the number of sides of the regular polygon, then the sum of the interior angles is (x - 2) * 180 = 56 * 90. Solving for x gives 30 for the number of sides of the regular polygon.
To get the central angles measure, divide 360 by 30 to get 12 degrees for the measure of one of the 30 central angles.
Answer: 12 degrees
The names PNM and MPN are perfectly valid. The order of the letters doesn't matter. In fact, there are 6 ways to name this plane if we just use the 3 letters. If we include "plane Z", then there are 7 total ways to name the plane.
For some reason, your teacher wants P to be the third letter as s/he mentioned MNP and NMP. But again, the order doesn't matter.