Three differentiated questions then reinforce understanding of angles in a triangle, use of a protractor and introduce an investigation about fitting different triangles into a 30cm square pizza box.

Angles in equilateral triangles The three angles in an equilateral triangle are equal and they add up to 180 ∘. To find the size of each of these angles divide 180 by 3. 180 ÷ 3 = 60 ∘ ...

This is in the Portail Royale of Chartres Cathedral. One to the square root of three For this proportion, draw an equilateral triangle of any size. Draw a line from the centre of the base to the apex.

Its premise is simple: Players are presented a geometric puzzle in the form of a task. The first level, for example, asks the player to construct an equilateral triangle from the line segment AB: ...

By placing this equilateral triangle between the legs of the figure, Leonardo achieves a specific proportion in the drawing. The side of the square compared to the radius of the circle yields a ...

It’s possible to construct a curve of constant width not only from an equilateral triangle but also from any polygon with an odd number of sides. Thus, you can readily obtain a curved pentagon ...