Reflection

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

Requirement:

Write a program that draws the reflection of the blue shape on the left about the y-axis line. Use two sprites drawing the blue and the red shapes simultaneously.

Testing examples:

There are no testing examples for this challenge.

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 for solution 1

when green flag clicked

when green flag clicked

clear

clear

set pen size to (3)

set pen color to [#2ca5e2]

pen down

pen up

set pen size to (3)

set pen color to [#db0705]

pen down

pen up

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

go to x: (0) y: (100)

go to x: (-100) y: (100)

go to x: (-100) y: (0)

go to x: (-100) y: (0)

go to x: (-200) y: (0)

go to x: (-200) y: (-100)

go to x: (0) y: (-100)

go to x: (0) y: (100)

go to x: (0) y: (100)

go to x: (100) y: (100)

go to x: (100) y: (0)

go to x: (100) y: (0)

go to x: (200) y: (0)

go to x: (200) y: (-100)

go to x: (0) y: (-100)

go to x: (0) y: (100)

Recommended blocks for solution 2

when green flag clicked

when green flag clicked

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

wait (1) secs

clear

set pen size to (3)

set pen color to [#05d382]

pen down

pen up

clear

set pen size to (3)

set pen color to [#e81818]

pen down

pen up

set [angle v] to [90]

set [mirror angle v] to ((360) - (angle))

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

point in direction (0 v)

move (100) steps

turn ccw (angle) degrees

move (100) steps

turn ccw (angle) degrees

move (100) steps

turn cw (angle) degrees

move (100) steps

turn ccw (angle) degrees

move (100) steps

turn ccw (angle) degrees

move (200) steps

turn ccw (angle) degrees

move (100) steps

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

point in direction (0 v)

move (100) steps

turn ccw (mirror angle) degrees

move (100) steps

turn ccw (mirror angle) degrees

move (100) steps

turn cw (mirror angle) degrees

move (100) steps

turn ccw (mirror angle) degrees

move (100) steps

turn ccw (mirror angle) degrees

move (200) steps

turn ccw (mirror angle) degrees

move (100) steps

Hints

Two different solutions to draw the shape and its reflection;

Solution 1: By drawing lines connecting the vertices (corners) using the “goto” block.
Solution 2: By moving steps and turning angles (each reflected angle is 180 - original angle).

Show Scratch solution