Extension and Dimension Lines
Extension and dimension lines are the two main types of lines used to show the exact size of an object on a drawing.
Think of them as a team working together to tell you how long, wide, or tall something is.
What is an Extension Line?
The Job: They show where a measurement starts and stops.
The Look: They are short, thin, solid lines.
The Position: They grow out from the edges of the drawing.
The Secret: They never actually touch the object's outline. A tiny gap is left so the drawing does not look messy.
What is a Dimension Line?
The Job: They show the distance between the extension lines.
The Look: They have sharp arrows on both ends.
The Position: They sit right between the extension lines, running sideways or up and down.
The Number: The actual size (like 5 cm) is written right in the middle of this line.
How They Work Together
Imagine you draw a special square decimeter:
1. You draw two extension lines reaching out from the left and right corners.
2. You draw a dimension line with arrows connecting those two lines.
3. You write "10cm" in the arrow line. Now everyone knows your square is 10 centimeters wide!
You have a square decimeter.
Think of them as a team working together to tell you how long, wide, or tall something is.
What is an Extension Line?
The Job: They show where a measurement starts and stops.
The Look: They are short, thin, solid lines.
The Position: They grow out from the edges of the drawing.
The Secret: They never actually touch the object's outline. A tiny gap is left so the drawing does not look messy.
What is a Dimension Line?
The Job: They show the distance between the extension lines.
The Look: They have sharp arrows on both ends.
The Position: They sit right between the extension lines, running sideways or up and down.
The Number: The actual size (like 5 cm) is written right in the middle of this line.
How They Work Together
Imagine you draw a special square decimeter:
1. You draw two extension lines reaching out from the left and right corners.
2. You draw a dimension line with arrows connecting those two lines.
3. You write "10cm" in the arrow line. Now everyone knows your square is 10 centimeters wide!
You have a square decimeter.
Extension
Dimension