# Tridots

## Find all the triangles that can be drawn by joining dots.

There is a printable worksheet to go with this activity.

## Investigate other polygons that can be drawn on a 3 by 3 grid.

#### Polygon Areas

Investigate which polygons have an area of 4 square units on this interactive dotty grid.

Transum.org/go/?to=areas

##### Suggested

Calculate the areas of all the possible quadrilaterals that can be constructed by joining together dots on this grid.

#### Area Two

How many different shapes with an area of 2 square units can you make by joining dots on this grid with straight lines?

Transum.org/go/?to=area2

All the possible triangles and the solutions to other Transum puzzles, exercises and activities are available here when you are signed in to your Transum subscription account. If you do not yet have an account and you are a teacher, tutor or parent you can apply for one by completing the form on the Sign Up page.

Investigations Home

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A mathematical investigation is quite different to other mathematical activities. The best investigations are open ended and allow students to choose the way they work and how they record their findings. It is one of the few occasions when 'going off on a tangent' is not only acceptable but actively encouraged (within reason).

Students may ask for 'the answers' but this supposes that the activity is closed. Investigations can always be extended by varying the initial instructions or asking the question 'what if...?'. Sometimes students point out that the instructions are ambiguous and can be interpreted in different ways. This is fine and the students are encouraged to explain how they interpreted the instructions in their report.

Some students may benefit from a writing frame when producing the reports of their investigations. Teachers may suggest sections or headings such as Introduction, Interpretation, Research, Working and Conclusion or something similar.

## Here are some other activities you may be interested in:

#### Suko Sujiko

Interactive number-based logic puzzles similar to those featuring in daily newspapers designed to develop numeracy skills. These puzzles are drag and drop and can earn you a Transum Trophy.

#### Snooker Angles

An online game for one or two players requiring an ability to estimate angles as bearings. So far this activity has been accessed 153846 times and 1956 Transum Trophies have been awarded for completing it.

For Students:

For All: