Rectangle :
Area = l×b
Perimeter = 2(l+b)
Square :
Area = a×a
Perimeter = 4a
Parallelogram
Area = l×h
Perimeter = 2(l+b)
Triangle :
Area =12×b×h or √s(s−a)(s−b)(s−c),where s=a+b+c2
Right angle Triangle :
Area =12×b×h
Perimeter = Sum of all sides
Isosceles right angle triangle :
Area = 12×b×h
Perimeter = 2a+d, where d=a√2
Equilateral Triangle :
Area = √34a2
Perimeter = 3a