A cоntinuоus beаm's flexurаl reinfоrcement must extend аt least _____ from the point where it is no longer needed to resist tension. Assume f'c = 4,000 psi, fyt = 40,000 psi, b1 = 21 in., b2 = 11 in., d = 27 in., h1 = 6 in., h2 = 17 in., h3 = 9 in., and t = 6 in. There are four No. 8 longitudinal tension bars and No. 4 stirrups at 10 in. o.c.