A triangle is a plane figure with straight sides and three angles. All of the interior angles add up to 180 degrees. A triangle is a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted \triangle ABC.
Area of triangle: [ l×b /2 ]
Perimeter of Triangle: [ (a + b + c) ]
Area of Equilateral Triangle: [ (Sqrt (3)/4)×(side)² ]
Area of Triangle SAS (2sides & opposite angle): [ ½×a×b×SinC ]
l = length
a,b and c = sides of the triangle