To Make Drawings Easy to Read
Just like how road maps use different lines for highways and small streets, technical drawings use different lines to help you quickly understand what's important
The dark, solid lines are like the main roads - they show the most important parts you can see
To Show Hidden Parts
Sometimes we need to show parts that are hidden inside or behind something
It's like being able to see through walls with X-ray vision, but we use dashed lines instead!
To Find the Middle
When you need to find the exact center of a circle (like when building a wheel), special lines called center lines show you where to look
It's like having a big "X marks the spot" on your drawing
To Help With Measuring
Different lines help show where to measure things
It's similar to having guide lines when you're learning to write in a notebook
Think of it like creating a secret code that everyone who builds things can understand - each type of line tells them something special about what they're building!