Triangles

problem

Cartesian Isometric

Age

7 to 11

Challenge level

The graph below is an oblique coordinate system based on 60 degree angles. It was drawn on isometric paper. What kinds of triangles do these points form?
problem

Triangle Pin-Down

Age

7 to 11

Challenge level

Use the interactivity to investigate what kinds of triangles can be drawn on peg boards with different numbers of pegs.
problem

Sticks and Triangles

Age

7 to 11

Challenge level

Using different numbers of sticks, how many different triangles are you able to make? Can you make any rules about the numbers of sticks that make the most triangles?
problem

Triangle Transformation

Age

7 to 14

Challenge level

Start with a triangle. Can you cut it up to make a rectangle?
problem

Threesomes

Age

11 to 14

Challenge level

Imagine an infinitely large sheet of square dotty paper on which you can draw triangles of any size you wish (providing each vertex is on a dot). What areas is it/is it not possible to draw?
problem

Dotty Triangles

Age

11 to 14

Challenge level

Imagine an infinitely large sheet of square dotty paper on which you can draw triangles of any size you wish (providing each vertex is on a dot). What areas is it/is it not possible to draw?
problem

Isosceles Meld

Age

11 to 14

Challenge level

Weekly Problem 9 - 2012
What is the angle QPT in this diagram?
problem

Stellar Angles

Age

11 to 14

Challenge level

Weekly Problem 30 - 2013
What is the angle $x$ in the star shape shown?
problem

Notes on a Triangle

Age

11 to 14

Challenge level

Can you describe what happens in this film?
problem

Triangular Tantaliser

Age

11 to 14

Challenge level

Draw all the possible distinct triangles on a 4 × 4 dotty grid. Convince me that you have all possible triangles.