Idea 15of 22Builds onAny side can be the base
Same base, same height, same area
Do shapes that lean further cover more space?
Today you'll discover
- what stays the same between two lines
- why the lean does not matter
- the same for triangles
Think firstA rectangle and two leaning shapes
All three stand on 4 cm bases between the same lines. Which covers the most area?
Decide first, then press Next. Measure the bases, then the gap between the two lines.
Two dashed lines run across a grid, 3 squares apart. Between them stand a rectangle and two parallelograms, each on a 4 cm base, the last leaning far. Blue dashed heights of 3 cm drop from each top, and under each shape the line 4 × 3 = 12 cm² appears. The last step shows three triangles on 6 cm bases between lines 4 cm apart.
See the whole ideathe big idea and the key word, in one place
The big idea
Shapes with the same base and the same height cover the same area, however far they lean.
See the patternBetween two parallel lines, every shape has the same height. Give them the same base too, and their areas match.
Easy to get wrongDon't judge area by how long a shape looks. Measure the base and the height.
Key word
- parallel lines
- lines that run side by side, always the same distance apart, and never meet
Ready to use it?
- Compare the areas of shapes with the same base and height.