Find the number of sides in a polygon, given information about diagonals

Problem involving perimeter and area of a regular hexagon

Find the ordered triple (x,y,z) given the information about the quadrilateral

Finding the median of a trapezoid, given information about the bases, the height, and the area

Find the area of the parallelogram, given information about its sides, and an altitude

Determine the number of sides in a polygon, given some information about the relationship between its sides and diagonals

Determine the number of diagonals in a polygon