Draw a regular polygon

Challenge Level: Growing experience

Learning outcomes

Students will be able to:

Describe how variables store values and how they are used in your program.
Computer Science: Programming
Explain how sequence works in programming.
Computer Science: Programming
Explain what you need to consider if you are asking for an input from the end user.
Computer Science: Programming
Identify how and when to use a loop to repeat a set of instructions.
Computer Science: Programming

Requirement:

Write a program that draws any regular polygon with the number of sides entered by the user as the input and the length of each sides equal to 50 steps.

Testing examples:

Test your program with 3, 5 and 10 number of sides as the input.

Languages

Scratch

What it should look like

Click on the green flag to see the expected output of your program.

View full screen

Recommended blocks

when green flag clicked

clear

pen down

pen up

set [sides v] to (answer)

go to x: (0) y: (0)

move (50) steps

turn cw ((360) / (sides)) degrees

say [I'll draw a polygon with the number of sides you give me.] for (3) secs

ask [Enter the number of sides:] and wait

repeat (sides)
end

Hints

A regular polygon has all angles equal and all sides equal.
The turning angle or external angle for a regular polygon can be calculated by dividing 360 by the number of sides of the polygon. Note that the turning angle at each vertex of the polygon is different from the inside or the interior angle (i.e. the turning angle and the inside angle of each vertex of the polygon add up to 180 degrees).
Block wait () secs waits specified number of seconds, then continues with next block. To be able to see each sides of the polygon being drawn, use the wait block after turning each angle.

Show Scratch solution

Extra Challenge

Extra challenge #1: Write a program that takes the length of a side of a polygon as the input, draws the polygon with the given side and displays its perimeter as the output.