I made shapes by matching the triangle to each side of the larger shape. I matched the different sides in length. Each side of the larger shape can only match to one side of the triangle as the triangle has 3 different sides (it is a scalene triangle).
This made 4 different shapes:
- a square (which we started with)
- a parallelogram (I wasn't sure at first if this was a rhombus, but the top and bottom are the sides of the square and the left and right sides are the hypotenuse of the triangle which must be longer)
- a scalene triangle
- an irregular quadrilateral
I then realised I could make more shapes if I flip the triangle over. I then did the same thing, which gave the following shapes:
- an irregular pentagon
- a different irregular pentagon
- another different irregular pentagon
- a trapezium
To finish, I thought about why flipping the triangle gives irregular pentagons when before I only had 3 or 4 sided shapes. This is because there are 7 total sides between the 2 shapes. When I match two sides, those both disappear, but for all of the first shapes, two sides end up joining together, meaning I lose one more side and get 4 sided shapes (or, with the triangle, two sides join together TWICE).