Idea: I want to draw a simple shape using Python.
Question to DeepSeek:
Draw an equilateral triangle with a side length of 3cm in Python.
The response given was, after trying left and right, I am still very confused.
Python draws a 3cm equilateral triangle
Python draws a 3cm equilateral triangle
Python draws an equilateral triangle with a side length of 3cm
Python draws an equilateral triangle
Here is the code to draw an equilateral triangle with a side length of 3cm using the Python matplotlib library:
python
import matplotlib.pyplot as plt
import numpy as np
# Set the figure size to ensure the display ratio is correct
plt.figure(figsize=(6, 6))
# Calculate the vertex coordinates of the equilateral triangle
# Assume the base is horizontally placed, with the two vertices of the base at
(-1.5, 0) and (1.5, 0)
# The height of the equilateral triangle
height = side_length * np.sqrt(3) / 2 # ≈ 2.598
side_length = 3
height = side_length * np.sqrt(3) / 2
# Vertex coordinates
x = [-side_length/2, side_length/2, 0, -side_length/2]
y = [0, 0, height, 0]
# Draw the triangle
plt.plot(x, y, ‘b-‘, linewidth=2)
# Set the axis aspect ratio to equal to ensure the shape is not distorted
plt.axis(‘equal’)
# Set the axis limits
plt.xlim(-2, 2)
plt.ylim(-0.5, 3)
# Add title and labels
plt.title(f’Equilateral Triangle (Side Length = {side_length}cm)’)
plt.xlabel(‘x (cm)’)
plt.ylabel(‘y (cm)’)
# Add grid
plt.grid(True, linestyle=’–‘, alpha=0.7)
# Show the figure
plt.show()
This code will draw an equilateral triangle with a side length of 3cm and ensure the display ratio is correct so that the triangle does not appear distorted.
If you want to represent the length of 3cm more accurately, you can use the conversion features of matplotlib, but be aware that the actual size displayed on the screen will be affected by the display device’s DPI.
Then I had to continue asking:
Where should I paste this code?
The answer is as follows:
This Python code can be pasted and run in several places:
1. Jupyter Notebook / JupyterLab (recommended)
Installation:
pip install jupyterlab
Start:
jupyter lab
Then create a new Notebook file and paste the code in a code cell to run it.
2. Python script file
Create a .py file (e.g., triangle.py)
Paste the code and save it.
Run it in the terminal/command line:
python triangle.py
3. Online Python environment
Google Colab: https://colab.research.google.com/
Replit: https://replit.com/
Paste and run directly.
4. Python IDE
PyCharm
VS Code (requires Python extension)
Spyder
Thonny
5. Simple online running method
If you want to run it immediately, here is a simplified version of the online code:
python
# Run at https://www.python.org/shell/ or similar online environments
import matplotlib.pyplot as plt
import numpy as np
side_length = 3
height = side_length * np.sqrt(3) / 2
x = [-side_length/2, side_length/2, 0, -side_length/2]
y = [0, 0, height, 0]
plt.plot(x, y, ‘b-‘, linewidth=2)
plt.axis(‘equal’)
plt.title(f’Equilateral Triangle (Side Length = {side_length}cm)’)
plt.grid(True)
plt.show()
It is recommended to use Jupyter Notebook as it is best suited for data visualization and learning Python. You need to install the necessary libraries first:
bash
pip install matplotlib numpy
Which method do you want to use to run it? If you need more detailed installation guidance, please let me know!
After trying a few more times, I continued to ask:
I already have Python and the VS CODE extension, what else do I need to install to draw?
The answer:
To run drawing code in VS Code, you need to install the following libraries:
Required library installation
Open the terminal in VS Code and run the following commands:
bash
# Install matplotlib (drawing library)
pip install matplotlib
# Install numpy (mathematical computation library)
pip install numpy
Steps to run in VS Code
Create a new Python file:
Create a new file and save it as triangle.py
Paste the complete code:
python
import matplotlib.pyplot as plt
import numpy as np
# Set Chinese font (to avoid Chinese display issues)
plt.rcParams[‘font.sans-serif’] = [‘SimHei’] # For normal display of Chinese labels
plt.rcParams[‘axes.unicode_minus’] = False # For normal display of negative signs
# Set figure size
plt.figure(figsize=(6, 6))
# Calculate the vertex coordinates of the equilateral triangle
side_length = 3
height = side_length * np.sqrt(3) / 2
# Vertex coordinates
x = [-side_length/2, side_length/2, 0, -side_length/2]
y = [0, 0, height, 0]
# Draw the triangle
plt.plot(x, y, ‘b-‘, linewidth=2)
# Set the axes
plt.axis(‘equal’)
plt.xlim(-2, 2)
plt.ylim(-0.5, 3)
# Add title and labels
plt.title(f’Equilateral Triangle (Side Length = {side_length}cm)’)
plt.xlabel(‘x (cm)’)
plt.ylabel(‘y (cm)’)
plt.grid(True, linestyle=’–‘, alpha=0.7)
# Show the figure
plt.show()
Run the code:
Press F5, or click the run button in the upper right corner, or
type in the terminal:
python triangle.py
If you encounter issues
If Chinese displays as boxes, install additional fonts:
bash
pip install matplotlib-font-manager
If it prompts that the module is not found, check the Python interpreter:
Press Ctrl+Shift+P
Type “Python: Select Interpreter”
Select the correct Python environment
After installation, you can run the drawing code in VS Code!
This time the answer gave me actionable steps, and following the prompts, I finally clicked the run button in the upper right corner of the VS CODE page, and after a while, a big triangle appeared. At that moment, I felt like I had found an oasis in the desert, and the joy after confusion surged. Actually, there was no specific purpose; I just wanted to use it while learning Python.
