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 # Math formulas
 ## Area
+S is the Area; π (pi) is a constant (approx 3.14159); R is the Radius; a is the length (or height), and b is the width (or breadth).
 - Circle: S = πR²
 - Rectangle: S = ab
 - Square: S = a²
 
 ## Perimeter
+P is Perimetr; π (pi) is a constant (approx 3.14159); R is the Radius;  is the length (or height), and b is the width (or breadth).
 - Circle: P = 2πR
 - Rectangle: P = 2a + 2b
 - Square: P = 4a