Master the fundamentals of turtle graphics with 100% textbook-accurate solutions for DAV Class 4 Hands-On: A Book of ICT Chapter 4: LOGO-I. Learn all basic LOGO primitives, full forms, short forms, angle calculations, Alice in Wonderland maze commands, and crossword puzzle answers.
Chapter Overview: Introduction to LOGO
Core Facts About LOGO:
- LOGO stands for Language of Graphics Oriented.
- It is an easy computer programming language designed for students to draw figures, write text, and perform calculations.
- A small triangle on the screen called the Turtle draws lines as it moves in response to instructions.
- The pointed top of the turtle is called its Head, and the flat bottom is called its Tail.
- Screen components: Graphics Screen (Main Screen) where the turtle draws, and Commander Window where commands are typed and executed.
LOGO Primitives: Full Forms & Short Forms (Textbook Page 58)
2. Expand the given terms: write the full forms and short forms of different primitives learnt:
| Short Form | Full Form (Primitive Name) | Description / Action |
|---|---|---|
| 1. RT | RIGHT | Turns the turtle’s head towards the right by a specified number of degrees. |
| 2. CT | CLEARTEXT | Clears all typed text and command history from the commander window. |
| 3. BK | BACKWARD (or BACK) | Moves the turtle backward by a given number of steps without turning its face. |
| 4. LT | LEFT | Turns the turtle’s head towards the left by a specified number of degrees. |
| 5. FD | FORWARD | Moves the turtle forward in the direction of its head by a given number of steps. |
| 6. CS | CLEARSCREEN | Erases all drawings from the graphics screen and brings turtle to home center. |
Write Suitable Commands (Textbook Page 58)
3. Write the suitable commands for the following operations:
| Operation Required | Exact LOGO Command |
|---|---|
| 1. To clear the command window | CT (ClearText) |
| 2. To rotate the Turtle towards its right direction | RT 90 (or RT <angle>) |
| 3. To bring the turtle back to its Home position | HOME |
| 4. To move the turtle in the backward direction | BK 50 (or BK <steps>) |
| 5. To erase everything on the screen | CS (ClearScreen) |
| 6. To move the turtle in the forward direction | FD 50 (or FD <steps>) |
Activity: Predict the Shape (Textbook Page 57-58)
1. When we enter the following commands (with the turtle at “home” pointing up), which shape appears?
FD 60,RT 90→ A vertical line going up by 60 units, then turtle turns 90° right (Right-angle corner pointing right).BK 50,LT 90,FD 60→ Turtle moves down 50 units, turns left 90°, and moves forward 60 units (Inverted step / L-shape).LT 45,FD 50,RT 90,FD 50→ Turtle turns left 45°, moves 50, turns right 90°, moves 50 (Inverted V / Mountain Peak shape).
Comparing Command Sets: Drawing Squares (Textbook Page 59)
4. Draw the shapes that you will get when you give the following commands and also name the shape thus obtained:
Command Set 1 (Right Turns)
? FD 100 ? RT 90 ? FD 100 ? RT 90 ? FD 100 ? RT 90 ? FD 100 ? HOME
Result: Draws a perfect square of size 100 on the right side of the starting vertical line.
Command Set 2 (Left Turns)
? FD 100 ? LT 90 ? FD 100 ? LT 90 ? FD 100 ? LT 90 ? FD 100 ? HOME
Result: Draws a perfect square of size 100 on the left side of the starting vertical line.
Textbook Questions Answered:
• The shapes obtained in both the cases are: Squares of side 100 units.
• Spot the difference between the two sets of commands: The two sets of commands differ by turn (direction) commands (RT turns the turtle clockwise to the right, whereas LT turns it anti-clockwise to the left).
Assessment Activity 1: Alice Maze to Wonderland (Textbook Page 60)
Question: Write the LOGO commands to help Alice find her way through the maze to wonderland:
; Step-by-Step LOGO Navigation for Alice Maze CS FD 40 ; Move forward into the first corridor RT 90 ; Turn right FD 30 ; Pass the obstacle wall LT 90 ; Turn left FD 60 ; Move straight through central corridor LT 90 ; Turn left into upper pathway FD 30 ; Advance towards upper chamber RT 90 ; Turn right facing Wonderland portal FD 40 ; Reach Wonderland!
Assessment Activity 2: Crossword Puzzle (Textbook Page 60)
| Clue Number & Direction | Crossword Clue | Answer Word | Letter Count |
|---|---|---|---|
| Across 2 | This key should be pressed after every command | ENTER | 5 letters |
| Across 3 | The window where the turtle draws | GRAPHICSCREEN | 13 letters |
| Down 1 | It is the home of the turtle | CENTER | 6 letters |
| Down 4 | It is the language of the Turtle | LOGO | 4 letters |
| Down 5 | The window where we type the commands | COMMANDWINDOW | 13 letters |
Frequently Asked Questions (FAQ)
Q1: What happens when you type HOME in LOGO?
Ans: The HOME command brings the turtle back to its initial starting position in the center of the graphics screen, pointing straight up, leaving a line behind as it moves.
Q2: What is the difference between CS and CT?
Ans: CS (ClearScreen) erases all drawings from the graphics screen and resets the turtle to center. CT (ClearText) clears all typed commands and text from the commander window.