MathDB
Right Triangles and an Octagon

Source:

June 8, 2009

Problem Statement

A regular octagon is to be formed by cutting equal isosceles right triangles from the corners of a square. If the square has sides of one unit, the leg of each of the triangles has length: (A)\ \frac{2 \plus{} \sqrt{2}}{3} \qquad (B)\ \frac{2 \minus{} \sqrt{2}}{2}\qquad (C)\ \frac{1 \plus{} \sqrt{2}}{2}\qquad (D)\ \frac{1 \plus{} \sqrt{2}}{3}\qquad (E)\ \frac{2 \minus{} \sqrt{2}}{3}