Classifying 2D Shapes — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. A rectangle has four right angles.
A rectangle is defined as a parallelogram with four right (90°) angles. Its opposite sides are equal and parallel.
2. A shape with four equal sides and four right angles is both a rhombus and a square.
A square meets the definition of both a rhombus (four equal sides) and a rectangle (four right angles). It is the most specific classification.
3. Opposite sides of a parallelogram are parallel and equal.
In a parallelogram, both pairs of opposite sides are parallel AND equal in length. This is a defining property.
4. A rhombus has 4 equal sides.
A rhombus has four equal sides. Unlike a square, a rhombus does not require right angles — its angles can vary as long as opposite angles are equal.
5. A quadrilateral with no parallel sides is called a general quadrilateral.
When a quadrilateral has no special parallel sides (not a trapezoid, parallelogram, etc.), it is simply called a general or irregular quadrilateral.
6. Every square is a special type of rhombus because it has four equal sides.
A rhombus requires four equal sides. Since a square also has four equal sides (plus right angles), every square is a rhombus, but not every rhombus is a square.
7. The diagonals of a rectangle are always equal in length.
In a rectangle, both diagonals are always equal in length. This is a unique property of rectangles among parallelograms.
8. A parallelogram has opposite angles that are equal.
In any parallelogram, opposite angles are equal in measure. Adjacent angles are supplementary (sum to 180°).
9. A trapezoid has exactly 1 pair(s) of parallel sides.
A trapezoid has exactly one pair of parallel sides (bases). The other pair of sides (legs) is not parallel, distinguishing it from a parallelogram.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Four right angles, opposite sides equal
→ Rectangle
Square
Exactly one pair of parallel sides
→ Trapezoid
Rhombus
Four equal sides, no right angles required
→ Rhombus
Rectangle
Four equal sides and four right angles
→ Square
Trapezoid
Four right angles, opposite sides equal = Rectangle; exactly one pair parallel = Trapezoid; four equal sides no right angles required = Rhombus; four equal sides AND right angles = Square.