Answer
quadrilateral;
pentagon;
hexagon;
heptagon;
octagon
Work Step by Step
RECALL:
The names of some polygons based on the number of sides:
octagon - eight sides
heptagon - seven sides
hexagon - six sides
pentagon - five sides
quadrilateral - four sides
Thus, the missing expression in the given statement are:
quadrilateral;
pentagon;
hexagon;
heptagon;
octagon