Is polygon always a plane figure?

A16 ounce bottle of orange juice says it contains 200 milligrams of vitamin c which is 250% uh just read the paper it explains it better

The highest point on earth is the peak of mount everest if you climb to the top you would be approximately 29,035 feet above sea level at remembering that amount is 5280 feet percentage of the height of the mountain would you have to climb to reach a point 2 miles above sea level

Before simplifying, how many terms are there in the expression 2x - 5y + 3 + x?