Ontario · Grade 8
G8.E1.3
Grade 8 — Use scale drawings to calculate actual lengths and areas, and reproduce a drawing at a different ratio.
A note on this mapping: Ontario has no similar-triangle criteria (AA, SSS, SAS) before Grade 10: dilations and scale drawings are as close as the elementary curriculum comes, and the formal treatment waits for MPM2D.
The skill that covers it
What a student should be able to do
- Identify similar triangles from angle relationships.
- Write and solve a proportion between corresponding sides, including the side-splitter, midsegment and angle-bisector theorems.
- Use a scale factor to find perimeters and areas.
- Solve indirect measurement problems such as shadow heights.