A **quadrilateral** is a polygon with four sides and four corners. Different types of quadrilaterals, namely, **the square, the rectangle, the parallelogram, the rhombus and the trapezium** are studied in CBSE class 9 mathematics.

The following are a few pointers for** formative assessment** activities that can be done to learn about different quadrilaterals.

**Discuss the different quadrilateral shapes around them:**Students can start the learning of different quadrilaterals by looking around them and identifying quadrilateral shapes. They will be surprised to find quadrilateral patterns all around them as geometry does exist all around us. It can vary from the rectangular shape of a notebook to an interesting trapezoid shape of a pencil box.**Draw the different quadrilaterals in notebook and measure sides and angles:**Students can then spend some time drawing a square, rectangle, parallelogram, rhombus and trapezium in their note-book and compare the different features of each quadrilateral. They can then measure the sides and angles of the different quadrilaterals that have been drawn. They can then write down the measurements in the following table.

Square | Rectangle | Parallelogram | Rhombus | Trapezium | |

Side 1 | |||||

Side 2 | |||||

Side 3 | |||||

Side 4 | |||||

Angle 1 | |||||

Angle 2 | |||||

Angle 3 | |||||

Angle 4 |

3. **Comparison of properties of different quadrilaterals:**

Students can then compare the properties of different quadrilaterals based on the measurements given. They can answer the following questions for each quadrilateral.

a) Are opposite sides equal?

b) Are opposite sides parallel?

c) Are adjacent sides equal?

d) Are all angles 90 degrees?

e) Do diagonals bisect each other?

f) Do diagonals bisect at 90 degrees?

g) Are opposite angles equal?

h) Do diagonals divide into two congruent angles?

i) Are diagonals equal in length?

4. **Making of a tangram-like puzzle and comparing and discussing quadrilateral shapes:** Students can then make a tangram-like puzzle and discuss the different quadrilateral shapes and patterns that they observe in the tangram. They can also make modifications of the seven-shaped tangram to include less or more pieces and make measurements and discuss properties of the different quadrilateral shapes. They can then make presentations and display their “tangrams.” This will further reinforce learning about different quadrilaterals and make the learning memorable.

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