IKMC 2005 - Grades 11-12 - Self-study Question 27

Question 27

ABCDEFGH is a regular octagon of side 1. P and Q are the indicated intersections of circles of radius 1 centred at A,B,C. Find angle APQ.

Question illustration

$\frac{19\pi}{24}$
$\frac{8\pi}{11}$
$\frac{5\pi}{8}$
$\frac{3\pi}{4}$
$\frac{7\pi}{9}$