GEOMETRIC REASONING - I

Exploring Matchstick Shapes

Task 1

Make a triangle, a square and a pentagon using the matchsticks and valve tubes.
(Connect two matchsticks using a cycle valve tube and make sure the sticks are inserted properly in the tubes to form the joints!)

Matchstick

Task 2

Make the following table in your notebook and fill in the table by performing the actions mentioned in the second left column.

SL. NO.	ACTION	DOES THE SHAPE CHANGE?	WHY DO YOU THINK SO?
1	Sliding the shape on the floor/desk
2	Rotating the shape on the floor/desk
3	Flipping the shape on the floor/desk
4	Pressing on the opposite vertices of the shape

What, according to you, is ‘shape’? What causes a ‘shape’ to change?

(Click here to write )

Task 3

Try pressing on the opposite vertices of the Pentagon. Does it change shape? Now try pressing a vertex and a side of the triangle. Does it change shape?

(Click here to write)

vertex

What will happen if you do the same with a hexagon? Which shape does not change when pressed? How might this property be useful to us?

Extension Task 1

Try making as many different shapes as possible by deforming/twisting the Pentagon (without breaking it or opening up the joints). In particular, try to make

a triangle that has exactly two sides equal
a four-sided polygon

Extension Task 2

Try making a triangle in which all three sides are of different length. What would be the minimum number of matchsticks needed for this?

(Click here to write)