Triangles

ABCDEFGH is a 3 by 3 by 3 cube. Point P is 1/3 along AB (that is AP : PB = 1 : 2), point Q is 1/3 along GH and point R is 1/3 along ED. What is the area of the triangle PQR?

How many triangles can you make using sticks that are 3cm, 4cm and 5cm long?

Can you describe what happens in this film?

A floor is covered by a tessellation of equilateral triangles, each having three equal arcs inside it. What proportion of the area of the tessellation is shaded?

Using LOGO, can you construct elegant procedures that will draw this family of 'floor coverings'?

Which of these triangular jigsaws are impossible to finish?

Can you make these equilateral triangles fit together to cover the paper without any gaps between them? Can you tessellate isosceles triangles?

Triangle ABC is an equilateral triangle with three parallel lines going through the vertices. Calculate the length of the sides of the triangle if the perpendicular distances between the parallel lines are 1 unit and 2 units.

What shapes can you make by folding an A4 piece of paper?

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