Or search by topic
The three triangles ABC, CBD and ABD are all isosceles. Find the angles in the triangles.
The sides AB and BC have lengths p and q respectively. Prove that the ratio p/q is equal to the golden ratio \frac{1}{2} (\sqrt{5}\ +1) .
and find the ratio q/p.The area of triangle ABC is 2 square units. Find the areas of CBD and ABD exactly (i.e. find the areas in the form a + b \sqrt{5}
Without using a calculator, computer or tables find the exact values of cos36cos72 and also cos36 - cos72.
Show that the arithmetic mean, geometric mean and harmonic mean of a and b can be the lengths of the sides of a right-angles triangle if and only if a = bx^3, where x is the Golden Ratio.