Geometry
This domain is about shape attributes and equal parts. You should identify quadrilaterals by their properties - parallel sides, right angles, equal sides - and partition shapes into parts with equal areas, naming each part as a unit fraction.
Core rules
- A quadrilateral has 4 sides and 4 angles; a rectangle has 4 right angles; a rhombus has 4 equal sides.
- A square is a special rectangle and a special rhombus, so it belongs in both groups.
- Shapes can share attributes without being identical.
- Partitioning a shape into 6 equal areas makes each part 1/6 of the whole, and 2 parts make 2/6.
Worked example
A rectangle is cut into 6 equal parts and 2 parts are shaded. Name the shaded fraction and an equivalent fraction. Reasoning: 6 equal parts means each part is 1/6, so 2 shaded parts are 2/6. Those 2 parts cover the same amount as 1/3 of the rectangle, so 2/6 = 1/3.
Traps that cost marks
- Saying a square is not a rectangle because it looks different.
- Accepting pieces that are the same shape but not the same area; fraction parts must have equal areas.
- Counting unshaded parts when the question asks about shaded parts.
- Treating a shape cut into 4 unequal pieces as showing fourths.