Q. What is this? A. A nonagon. Q. Why is it called a nonagon? A. Because it has nine sides and nine angles. Q. What does a nonagon mean? A. A nine-sided figure. Q. What is an irregular nonagon? A. A nine-sided figure whose sides and angles are not equal.
Dec-agon.
Q. What is this? A. A regular decagon. Q. What does a decagon mean? A. A ten-sided figure. Q. Why is it called a decagon? A. Because it has ten sides and ten angles, and there are both regular and irregular decagons.
Rect-angle or Oblong.
Q. What is this? A. A rectangle or oblong. Q. How many sides and angles has it? A. Four, the same as a square. Q. What is the difference between a rectangle and a square? A. A rectangle has two long sides, and the other two are much shorter, but a square has its sides equal.
Rhomb.
Q. What is this? A. A rhomb. Q. What is the difference between a rhomb and a rectangle? A. The sides of the rhomb are equal, but the sides of the rectangle are not all equal. Q. Is there any other difference? A. Yes, the angles of the rectangle are equal, but the rhomb has only its opposite angles equal.
Rhomboid.
Q. What is this? A. A rhomboid. Q. What is the difference between a rhomb and a rhomboid? A. The sides of the rhomboid are not equal, nor yet its angles, but the sides of the rhomb are equal.
Trapezoid.