WEBVTT

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Advanced functions, parameters and return values.

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In this video, we will understand how to use function parameters,

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learn how to return multiple values from a function,

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and use loops to allow repeated execution of the program.

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This program helps us calculate the area and perimeter of different shapes.

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We use it to understand how functions take parameters,

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process values, and return results for further use.

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Define a function.

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The program defines a function, calculate polygon sides

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that takes one parameter sides to determine the type of shape.

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Inside the function, if sides equals to zero, it prints no polygon,

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and returns, none common none, means no calculations.

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Else if, sides equal to three.

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Triangle, the user enters three side lengths,

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and the function calculates, perimeter equal to sum of all three sides.

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Area equal to base into height divided by two, assuming two sides form the base and height.

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Else if, sides equals to four.

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If the user enters four, they are prompted to choose between a square, s, or rectangle,

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R, and then enter required values.

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However, if the user enters a number other than zero, three, or four,

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the program displays a message, invalid number of sides.

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Please enter zero, three, or four.

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In all valid cases, the function calculates and returns the area and perimeter

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as a tuple containing both values.

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Handling user input.

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The program asks for user input.

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Use input function to decide which shape they want to calculate.

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It converts numerical inputs using float to ensure calculations work correctly.

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For four sided shapes, it asks the user to choose between square or rectangle before taking inputs.

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Using a loop to repeat the program.

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The main function contains a while-true loop, ensuring the program runs continuously

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until the user decides to stop.

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It calls, calculate polygon's sides function,

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stores the returned values, and displays them.

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The loop continues until the user enters no when asked if they want to continue.

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Understanding return values.

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The program checks if the returned values are not none before printing them.

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If valid, it displays, area and perimeter, using print function.

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Since the function returns values instead of printing them,

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the main program can use these values flexibly.

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After every calculation, the user is asked if they want to continue.

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If they enter no, the program thanks them and exits.

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This program teaches the importance of parameters and return values,

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helping students understand how functions can process and return useful data

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for further use in Python programs.