Formula

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 ]

Where,
l = length
b =breadth
a,b and c = sides of the triangle