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 = 6,000 psi, fyt = 40,000 psi, b = 12 in., d = 18 in., and that there are four No. 8 longitudinal tension bars and No. 5 stirrups at 7 in. o.c. The stirrup hooks are 135°.