Formula Centre

Formula guides and key subject rules for every grade and subject, with worked examples and practice.

Grade 10 Engineering Graphics and Design essentials

Engineering Graphics and Design • Essential reference • Grade 10

Scale = Drawing length / Actual length
Drawing lengthLength shown on the drawing (mm)
Actual lengthReal-world length (mm)

When to use it

Use to create or interpret scaled technical drawings.

Worked example

50 mm / 500 mm = 1:10 scale.

Common mistakes

  • Using different units for the two lengths.

Practice question

Convert 2 m to a 1:20 drawing length.

Grade 11 Engineering Graphics and Design essentials

Engineering Graphics and Design • Essential reference • Grade 11

Scale = Drawing length / Actual length
Drawing lengthLength shown on the drawing (mm)
Actual lengthReal-world length (mm)

When to use it

Use to create or interpret scaled technical drawings.

Worked example

50 mm / 500 mm = 1:10 scale.

Common mistakes

  • Using different units for the two lengths.

Practice question

Convert 2 m to a 1:20 drawing length.

Grade 12 Engineering Graphics and Design essentials

Engineering Graphics and Design • Essential reference • Grade 12

Scale = Drawing length / Actual length
Drawing lengthLength shown on the drawing (mm)
Actual lengthReal-world length (mm)

When to use it

Use to create or interpret scaled technical drawings.

Worked example

50 mm / 500 mm = 1:10 scale.

Common mistakes

  • Using different units for the two lengths.

Practice question

Convert 2 m to a 1:20 drawing length.