Curriculum placement
Grade 7. This describes the skill, not a learner estimate.
Scale drawings of lengths and areas
Use scale factors to recover lengths and areas
Problem types
- Lengths and areas from a scale drawing
- Show the work: lengths, areas and a new scale
Builds on
- Representing a proportional relationship
- Area of triangles and other polygons
- Converting within one measurement system · Useful idea
A scale drawing with a scale in different units needs a unit conversion before lengths compare.
- Additive and multiplicative comparison · Useful idea
A scale factor says one length is a number of times another, which is a multiplicative comparison.
- Perimeter of a polygon · Useful idea
Scaling a figure by a factor scales its perimeter by the same factor.
- Measuring length with a ruler · Useful idea
A scale drawing is measured with a ruler and the measured length is scaled to the real length.
Leads to
Related skills
- Dividing a segment in a given ratio · Related idea
A point a fraction of the way along a segment is found by scaling the displacement, as a scale drawing scales distances.
- Vectors and their components · Related idea
Scaling a drawing multiplies each length by the scale factor, as multiplying a vector by a number scales its components.
- The Pythagorean theorem · Shared foundations
- Slope of a line · Shared foundations
- Surface area of prisms and pyramids · Shared foundations
Open the interactive map to explore lessons and skill connections.