Linear dimension in AutoCAD - Cell-by-Cell Formula Trace

Sample Data

Coordinates of two points in 2D space and a cell to calculate the linear dimension (distance) between them.

Cell	Value
A1	Point 1 X
B1	Point 1 Y
A2	2
B2	3
A3	Point 2 X
B3	Point 2 Y
A4	7
B4	11
C1	Linear Dimension
C2
C3
C4

Formula Trace

SQRT( (A4 - A2)^2 + (B4 - B2)^2 )

Step 1: A4 - A2

Step 2: 7 - 2

Step 3: (A4 - A2)^2

Step 4: 5^2

Step 5: B4 - B2

Step 6: 11 - 3

Step 7: (B4 - B2)^2

Step 8: 8^2

Step 9: (A4 - A2)^2 + (B4 - B2)^2

Step 10: 25 + 64

Step 11: SQRT(89)

Cell Reference Map

     A     B     C
  +-----+-----+---------+
1 | Pt1X| Pt1Y| Linear  |
  |  2  |  3  | Dimension|
  +-----+-----+---------+
2 |  2  |  3  |         |
  +-----+-----+---------+
3 | Pt2X| Pt2Y|         |
  |  7  | 11  |         |
  +-----+-----+---------+
4 |  7  | 11  |  9.43   |
  +-----+-----+---------+

Arrows: C4 depends on A2, A4, B2, B4 for calculation.

The formula uses the X and Y coordinates of Point 1 (A2, B2) and Point 2 (A4, B4) to calculate the linear dimension in C4.

Result

     A     B     C
  +-----+-----+---------+
1 | Pt1X| Pt1Y| Linear  |
  |  2  |  3  | Dimension|
  +-----+-----+---------+
2 |  2  |  3  |         |
  +-----+-----+---------+
3 | Pt2X| Pt2Y|         |
  |  7  | 11  |         |
  +-----+-----+---------+
4 |  7  | 11  |  9.43   |
  +-----+-----+---------+

The linear dimension between the two points is approximately 9.43 units.

The final calculated linear dimension is shown in cell C4.

Sheet Trace Quiz - 3 Questions

What is the difference in X coordinates between Point 2 and Point 1?

A 9

B 7

C 5

D 8

Key Result

Linear dimension = SQRT( (X2 - X1)^2 + (Y2 - Y1)^2 )

Practice

1. What does a linear dimension in AutoCAD represent?
DIMLINEAR is used to create it.

easy

A. The straight distance between two points

B. The angle between two lines

C. The radius of a circle

D. The area of a shape

Solution

1. Step 1: Understand the purpose of linear dimension

   Linear dimension measures the straight distance between two points in a drawing.

2. Step 2: Recognize the command used

   DIMLINEAR is the AutoCAD command to create linear dimensions.

3. Final Answer:

   The straight distance between two points -> Option A

4. Quick Check:

   Linear dimension = straight distance [OK]

Hint: Linear dimension always measures straight distance [OK]

Common Mistakes:

• Confusing linear dimension with angular dimension
• Thinking it measures radius or area
• Mixing up commands like DIMANGULAR

2. Which of the following is the correct command to create a linear dimension in AutoCAD?

easy

A. DIMANGULAR

B. DIMDIAMETER

C. DIMRADIUS

D. DIMLINEAR

Solution

1. Step 1: Recall AutoCAD dimension commands

   DIMLINEAR is used for linear dimensions, DIMANGULAR for angles, DIMRADIUS for circle radius, and DIMDIAMETER for circle diameter.

2. Step 2: Match command to linear dimension

   Since linear dimension measures straight distance, the correct command is DIMLINEAR.

3. Final Answer:

   DIMLINEAR -> Option D

4. Quick Check:

   Linear dimension command = DIMLINEAR [OK]

Hint: DIMLINEAR command creates straight distance dimensions [OK]

Common Mistakes:

• Choosing DIMANGULAR which measures angles
• Confusing radius and diameter commands
• Typing commands with typos

3. Given two points at coordinates (2,3) and (8,7), what will the linear dimension show as the distance?

medium

A. 10 units

B. 7 units

C. 6.4 units

D. 5 units

Solution

1. Step 1: Calculate the distance between points (2,3) and (8,7)

   Use the distance formula: sqrt((8-2)^2 + (7-3)^2) = sqrt(6^2 + 4^2) = sqrt(36 + 16) = sqrt(52) ≈ 7.211.

2. Step 2: Check options for closest value

   Compare to ≈7.211: 7 units (closest, diff ≈0.211), 10 units (too high), 6.4 units (diff ≈0.811), 5 units (too low).

3. Step 3: Recalculate carefully

   sqrt(52) ≈ 7.211, so 7 units is closest to actual distance.

4. Final Answer:

   7 units -> Option B

5. Quick Check:

   Distance formula = 7 units [OK]

Hint: Use distance formula sqrt((x2-x1)^2+(y2-y1)^2) [OK]

Common Mistakes:

• Using wrong coordinates order
• Forgetting to square differences
• Choosing approximate values without calculation

4. You used DIMLINEAR but the dimension line is not showing the correct distance. What could be the issue?

medium

A. You selected points that are not aligned horizontally or vertically

B. You used the wrong command; should use DIMANGULAR

C. You forgot to set the scale factor

D. You did not select the dimension style

Solution

1. Step 1: Understand DIMLINEAR behavior

   DIMLINEAR measures horizontal or vertical distance between points. If points are diagonal, it may not show expected distance.

2. Step 2: Identify common mistake

   If points are not aligned horizontally or vertically, the dimension line may appear incorrect or skewed.

3. Final Answer:

   You selected points that are not aligned horizontally or vertically -> Option A

4. Quick Check:

   DIMLINEAR needs horizontal/vertical points [OK]

Hint: DIMLINEAR works best with horizontal or vertical points [OK]

Common Mistakes:

• Using DIMANGULAR instead of DIMLINEAR
• Ignoring scale factor settings
• Not applying dimension style

5. You want to dimension a slanted line between points (1,1) and (4,5) using DIMLINEAR. How do you ensure the dimension line shows the true length of the line?

hard

A. Use DIMLINEAR only between points aligned horizontally

B. Use DIMANGULAR to measure the angle instead

C. Use DIMLINEAR with the rotated option aligned to the line angle

D. Use DIMRADIUS to measure the length

Solution

1. Step 1: Understand limitation of DIMLINEAR

   DIMLINEAR measures horizontal or vertical distances by default, so for slanted lines, it needs rotation.

2. Step 2: Use rotated dimension option

   DIMLINEAR has a rotated option to align the dimension line along the angle of the slanted line, showing true length.

3. Step 3: Confirm other options are incorrect

   DIMANGULAR measures angles, not length; DIMRADIUS measures circle radius; horizontal alignment only works for horizontal lines.

4. Final Answer:

   Use DIMLINEAR with the rotated option aligned to the line angle -> Option C

5. Quick Check:

   Rotated DIMLINEAR shows true length [OK]

Hint: Rotate DIMLINEAR to line angle for true length [OK]

Common Mistakes:

• Using DIMANGULAR instead of linear dimension
• Trying to dimension slanted line without rotation
• Confusing radius with length measurement