kill(all)$

van=facebook.com/LearningCalculus$

r5:sqrt(2)/sqrt(5-sqrt(5));float(r5);

r7:1/(2*cos((5*%pi)/14));float(r7);

s5:(1+sqrt(5))/2;

s7a:sqrt(1-cos((8*%pi)/7))/
    sqrt(cos((5*%pi)/7)+1); float(%);

s7b:sqrt(1-cos((4*%pi)/7))/
    sqrt(cos((5*%pi)/7)+1); float(%);

s7b/s7a; float(%);