Find the circumradius of triangle ABC if AB=BC=29 and AC=40.

Circumradius =  product of the sides  /   (4 * area)

Height =  sqrt [ 29^2 - 20^2 ] =  sqrt [ 441] =  21

Area  = (1/2) (40) ( 21)  =  420

Circumradius  =      29^2 * 40  / (4* 420)  =  841/42  ≈  20.02