◆Definition of a polygon:- A polygon is any 2-dimensional shape formed with straight lines, such that triangles quadrilaterals Pentagons and hexagons etc. ◆Definition of A Triangle :- A three sided polygon is called triangle. ◆Definition of A Scalene Triangle :- A triangle having three unequal sides is called scalene triangle. ◆Definition of A Isosceles Triangle:- A triangle having any two sides equal is called Isosceles triangle. ◆Definition of A Equilateral Triangle :- A triangle having all sides equal is called equilateral triangle. ◆Definition of A Acute Angled Triangle:- A triangle having all the three acute angles is acute angle is called acute angled triangle. ◆Definition of A Obtuse angled triangle :- A triangle having any one Obtuse angle is called obtuse angled triangle. ◆Definition of A Right angled triangle :- A triangle having one angle as right angle is called right angled triangle. ◆Perimeter of a Triangle :- The sum of all the three si