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?
Investigate the different ways of cutting a perfectly circular pie into equal pieces using exactly 3 cuts. The cuts have to be along chords of the circle (which might be diameters).
How can you make an angle of 60 degrees by folding a sheet of paper
from Del Hawley
The three corners of a triangle are sitting on a circle. The
angles are called Angle A, Angle B and Angle C. The dot in the
middle of the circle shows the centre. The counter is measuring the
size of Angle A in degrees.
What is the smallest Angle A can be?
What is the largest Angle A can be?
What else do you notice about Angle A as you move the corners of
the triangle around the circle?
This problem is interactive, which means that you can move parts
of the picture around and see what happens. Just click and drag the
corners of the triangle.