A polygon is a closed figure formed by line segments. At least three line segments are needed to form a polygon.
Kinds of Polygons:
No. of Sides
|
Polygons
|
3
4
5
6
7
8
9
10
11
12
|
Triangle
Quadrilateral
Pentagon
Hexagon
Heptagon
Octagon
Nonagon
Decagon
Undecagon
Dodecagon
|
TRIANGLE is a polygon of 3 sides.
Kinds:
1. Scalene triangle has no two sides congruent or the measure of the sides are not equal.
2. Isosceles triangle has 2 congruent sides or the measures of two sides are equal.
QUADRILATERAL is a polygon of four sides.
QUADRI means 4 lateral sides.
Kinds:
1. Parallelogram has 2 pairs of parallel sides and opposite sides are congruent. It has length and width with one pair of obtuse angles and one pair of acute angles.
2. Rectangle has length and width. The opposite sides are congruent and has 4 right angles and 2 pairs of parallel sides.
3. Square has 4 congruent sides and 4 congruent angles. It has 2 pairs of parallel sides.
4. Rhombus has 4 congruent sides, 2 pairs of parallel sides, 1 pair of obtuse angle and 1 pair of acute angle.
5. Trapezoid has 1 pair of parallel sides.
In isosceles trapezoid the non-parallel sides are congruent.
6. Trapezium has no pair of parallel sides.
