Q.Program 7-2: Program to calculate the payable amount for the tent using user defined functions.

Program 7-2 restructures Program 7-1 into user-defined functions — one per computation — so each formula is named, reusable and testable.

def cyl_area(h, r):                 # curved surface of cylinder
    return 2 * 3.14 * r * h

def cone_area(l, r):                # curved surface of cone
    return 3.14 * r * l

def post_gst_price(cost):           # add 18% GST
    return cost + 0.18 * cost

h = float(input("Height of cylindrical part (m): "))
r = float(input("Radius (m): "))
l = float(input("Slant height of cone (m): "))
price = float(input("Cost of 1 sq m canvas (Rs.): "))

canvas_area = cyl_area(h, r) + cone_area(l, r)
print("Canvas area:", round(canvas_area, 2), "sq m") …

The idea. This pair of programs is the textbook's demonstration of why functions exist: identical functionality, but each formula now lives in a named function with parameters and a return value. If tomorrow the tent gains a second cylindrical section, you call cyl_area() again instead of copying code.

# Program 7-2: payable amount for the tent (using user-defined functions)

def cyl_area(h, r):
    """Curved surface area of a cylinder."""
    return 2 * 3.14 * r * h

def cone_area(l, r):
    """Curved surface area of a cone (l = slant height)."""
    return 3.14 * r * l

def post_gst_price(cost):
    """Add 18% GST to the cost and return the payable amount."""
    return cost + 0.18 * cost

# main program
h = float(input("Enter height of the cylindrical part (in m): "))
r = float(input("Enter radius of the tent (in m): "))
l = float(input("Enter slant height of the conical part (in m): "))
unit_price = float(input("Enter cost of 1 sq m of canvas (Rs.): "))

canvas_area = cyl_area(h, r) + cone_area(l, r)
print("Area of canvas needed:", round(canvas_area, 2), "sq m")

net_cost = canvas_area * unit_price
print("Cost of canvas       : Rs.", round(net_cost, 2))
print("Payable amount (incl. 18% GST): Rs.", round(post_gst_price(net_cost), 2))

Key lines

• Each function takes exactly the values it needs as parameters and returns the result — no printing inside, so the functions stay reusable.
• The main program reads the inputs, composes the functions (cyl_area(h, r) + cone_area(l, r)), and handles all display. …