Since being posted, the image has attracted over 150 comments, with users debating the correct number of triangles. Answers ...

You can split a rectangle into 2 right-angled triangles. Image caption, STEP 2: Use the compass to draw a circle. Put a dot where the compass rested and use the ruler to draw a horizontal line ...

Brainteasers have been proven to improve your lateral thinking skills and proponents claim they can even slow brain ageing – so why not give this challenge a go?

The sides of right-angled triangles are labelled opposite, hypotenuse and adjacent. Trigonometry explores the relationship between sides and angles in right-angled triangles. The hypotenuse is the ...