Question

if the side of a regular pentagon is a and its diagonal is of length b then a^2/b^2+b^2/a^2 is equal to what

Answer 1

I am assuming you need to use the cosine rule of triangles on this one.

Answer 2

@siddharth i like the AM >= GM argument for the last one . wouldn't have thought of it but i wrote a solution using that one too

Answer 3

how do we get the angles to be 144 and 18

Answer 4

Made a mistake. 72 is the angle with the center of the pentagon.

You find it by dividing 360 by five as there are five sides.

Answer 5

ok