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Answer these 10 questions to test your understanding of Block Programming when using Scratch.
For each of the following flowcharts complete the matching prediction table to work out the expected output based on the given input values.
Are you confident with your understanding of computer graphics? Can you explain the difference between bitmap graphics and vector-based graphics?
Computer GraphicsOpen Crossword Puzzle in a New Window
It’s almost impossible to discuss graphics software without first establishing an understanding of the differences between the two major graphic types: bitmap and vector images.
The following “fill in the blank” activities will test your understanding of the characteristics of both types of graphics.
Bitmap images (also known as images) are made up of in a grid. Pixels are picture elements; of individual colour that make up what you see on your screen. Pixels are defined by 2 properties: their position on the picture/grid and their colour value. These properties are stored in a bitmap file for every single pixel in the picture.
The colour value of each pixel is determined by the RGB colour code. (Red Blue). Each colour is made of a mix of these 3 primary colours. Each of these 3 colour have a value between 0 and 256. Hence a bitmap can have up to 256* 256 * 256 = 16 possible shades.
| Red: (255, 0, 0) | Purple: (85,0,85) |
| Yellow: (255,255,0) | White: (255,255,255) |
| Cyan: | Black: |
When you use a camera or a or a graphic tablet you create bitmap pictures.
Bitmap pictures come under different file extensions: BMP, GIF, JPEG, , TIFF.
The quality of a bitmap file is determined by its which tells you how many pixels the bitmap is made of. For instance a digital camera can have an resolution.
All these geometric based data is saved in a vector based graphics as instructions such as:
DrawLine Red, 1 pixel wide, 10 pixels long From position x=20 y=40
When editing a vector based graphics each object can be edited individually. Objects can also be to be moved/resized/rotated together.
Cliparts from the clipart tend to be vector based. are also vector based.
Vector based graphics do not loose quality or pixelate when they are resized as opposed to bitmap graphics which do or become blurry when they are enlarged or resized. Vector based cannot be as opposed to bitmap files which can be compressed (by loosing some quality)
Vector based files tend to take up less disk space than bitmaps. However Vector based graphics requires more power to be displayed on the screen.
Create your own vector graphics online using vecteezy.com
When programming a computer system, it is good practice to include a range of validation checks in the code to check if the data being inputted by the end-user follows some basic rules.
The aim of validation checks is to ensure that data used or stored by computer systems is valid. Invalid data may indeed make the system crash or may provide inaccurate information back to the user.
Validation checks cannot confirm if the data is correct or not but they can filter out a lot of invalid data.
There are different types of checks that can be implemented in your code such as:
Vera Molnár (born 1924) is a French media artist of Hungarian origin. She is considered to be a pioneer of computer art. Trained as a traditional artist, she began working with computers in 1968, where she began to create algorithmic paintings based on simple geometric shapes and geometrical themes.
In this blog post we are looking at using Python Turtle to recreate some of her artwork. To create you own op art/computer art, you will need to be confident in using iterative algorithms and have a good understanding of Cartesian coordinates.
To find review some of Vera Molnár’s artwork you can use the following pages:
Find more work from Vera Molnár on Google Images
In this challenge we will create a library of functions to apply the different formulas based on the geometry of triangles.
For each function, you will need to design the algorithm using either Pseudo-code or a flowchart, implement the function using the Python trinket provided below and use another algorithm to test your function.
Write a function called getPerimeter() that takes three parameters/arguments a, b, c (the length of each side of a triangle).
Your function should calculate and return the perimeter of this triangle.
Write an algorithm to test your function.
Your algorithm should:
Write a function called getArea() that takes two parameters/arguments corresponding to the length of the base and of the height of a triangle.
Your function should calculate and return the area of this triangle.
Write an algorithm to test your function.
Your algorithm should:
Write a function called getAngle() that takes two parameters/arguments called angle1 and angle2 (the value of two angles in degrees)
Your function should calculate and return the value of the third angle: (180 – angle1 – angle2)
Write an algorithm to test your function.
Your algorithm should:
Write a function called isEquilateral() that takes three parameters a, b, c (the length of each side of a triangle).
Your function should workout if the triangle is equilateral (if all sides have the same length) and return a Boolean value (True or False) based on its finding.
Write an algorithm to test your function.
Your algorithm should:
Write a function called isIsoscles() that takes three parameters a, b, c (the length of each side of a triangle).
Your function should workout if the triangle is an isosceles triangle (if any two sides have the same length) and return a Boolean value (True or False) based on its finding.
Write an algorithm to test your function.
Your algorithm should:
Write a function called getHypotenuse() that takes two parameters/arguments called a and b (the length of two sides of a right-angled triangle).
Your function should calculate and return the length of the third side (the hypotenuse) of the triangle knowing that:
Write an algorithm to test your function. Your algorithm should:
Write a function called isRightAngledTriangle(), that takes three parameters a, b and c and works out if the triangle is a right-angled triangle or not. Your function should return a Boolean value (True or False) based on its finding.
Write an algorithm to test your function. Your algorithm should:
Your function will apply Heron’s formula to calculate and return the area of the triangle.
Write an algorithm to test your function.
Your algorithm should:
Your task is to complete this Python script to create and test all the functions mentioned above.
The Heron’s formula is a famous formula used to calculate the area of a triangle based on the length of its three sides. It is called “Heron’s Formula” (sometimes called Hero’s formula) after Hero of Alexandria who was a Greek Engineer and Mathematician in 10 – 70 AD.
You will also then need to create a small program that will:
| Test # | Input Values (in cm) | Expected Output (in cm2) | Pass/Fail? |
| #1 | First side: 3 Second side: 4 Third side: 5 |
Area: 6 | |
| #2 | First side: 8 Second side: 10 Third side: 12 |
Area: 39.686 | |
| #3 | First side: 4 Second side: 8 Third side: 10 |
Area: 15.199 |
Illustration of Hero’s Aeolipile (Steam Engine)
For this programming challenge we will investigate different functions which will all be based on a linear search algorithm.
Let’s consider a teacher who has decided to keep track of rewards issued to their students throughout the term by adding their name at the end of a text file each time they win a reward for their positive attitude and effort in lessons.
The teacher would like to write a few Python functions to:
The teacher has started the code by creating a function called readTextFile() that takes a parameter called filename/ This function scan the context of the text file and return a list of all the names listed in the text file.
Using flowcharts, the teacher then worked out the algorithms for the extra functions they would like you to implement and test to complete the code. You can access these flowcharts below.
for value in list: print(value)
Not all programming languages will let you use this syntax. An alternative approach is to use indices:
for i in range(0,len(list)): print(list[i])
In this case the flowchart for our count() function would become:
A leap year is a calendar year that contains an additional day (29th of February) added to keep the calendar year synchronised with the astronomical year or seasonal year (which contains roughly 365¼ days or 365.242375 days to be more accurate).
An easy way to work out if a year is a leap year or not is to check if the year (e.g. 2020) is a multiple of 4. If it is, then it is most likely a leap year. Indeed, the rule is slightly more complex than this and can be summarised in three statements:
In Python to work out if a number is a multiple of 4, we can calculate the remainder (MOD) of dividing this number by 4. If this remainder is equal to zero, then the number is a multiple of 4.
Based on this we can create a small function that will take a number (year) as a parameter and return whether the given year is a leap year or not. Here is the flowchart for this function called isLeapYear():
We can then this function in any program where we need to work out if a year is a leap year or not. For instance, we can create a program that:
Here is the flowchart for this program:
| Test # | Input Values | Expected Output | Pass/Fail? |
| #1 | Year: 2020 | 2020 is a leap year. It contains 366 days. |
|
| #2 | Year: 2021 | 2021 is not a leap year. It contains 365 days. |
|
| #3 | Year: 2056 | 2056 is a leap year. It contains 366 days. |
|
| #4 | Year: 2100 | 2100 is a not a leap year. It contains 365 days. |
|
| #5 | Year: 2400 | 2400 is a leap year. It contains 366 days. |
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