Find the messure of an interior angle of a regular polygon with 13 sides

What percent of the circle below is shaded?

Acylinder with a base diameter of x units has a volume of jxcubic units which statements about the cylinder are true? check all that apply. the radius of the cylinder is 2 x units. the radius of the cylinder is 2x units. the area of the cylinder's base is 200 square units. the area of the cylinder's base is a square units. the height of the cylinder is 2x units. the height of the cylinder is 4x units. mark this and return save and exit next submit

The angle of elevation from point a to the top of a cliff is 38 degrees . if point a is 80 feet from the base of the cliff , how high is the cliff ?