To calculate perimeter/circumference and area of shapes such as triangle, rectangle, square and circle.

import math

# Rectangle
l = float(input("Length: "))
b = float(input("Breadth: "))
print("Rectangle Area =", l * b)
print("Rectangle Perimeter =", 2 * (l + b))

# Square
s = float(input("Side: "))
print("Square Area =", s * s)
print("Square Perimeter =", 4 * s)

# Circle
r = float(input("Radius: "))
print("Circle Area =", math.pi * r * r)
print("Circumference =", 2 * math.pi * r)