Page 141 - Math Skill - 4

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Simple Closed Figures
Look at the following figures.

A B C D

E F G H

Which of the figures given above could we draw by starting at same point, never lifting your
pencil from the paper and end at the starting point?
Obviously A, B, C, D, E, F, G and H. Such figures are called closed figures.

Out of these, which figures can we draw without having the figure crossed itself?
Obviously A, B, D, H. Such figures are called simple closed figures.

Polygons
Look at the figures below. They are all closed figures. But there is a difference, what is it?

(a) (b) (c) (d) (e) (f)
Figures (a), (d), (e) and (f) are made up of straight lines only.

But (b) and (c) are made up of curved lines. Fact-o-meter
Figures made up of only line segments as their sides are A polygon is a plane
called polygons. closed figure having
Polygons are named according to the number of their sides. three or more sides.

Some examples of polygons are given below.

Number of 3 4 5 6 7 8
sides

Figure of the
polygon

Name of the
polygon Triangle Quadrilateral Pentagon Hexagon Heptagon Octagon