Answer:
Tangent B = AB/BC = (67^(1/2))/(78^(1/2))
To simplify this fraction, we can multiply both the numerator and denominator by the square root of the denominator's denominator (in this case, 78^(1/2)), which will cancel out the square root in the denominator:
Tangent B = (67^(1/2))/(78^(1/2)) * (78^(1/2))/(78^(1/2)) = (67)/78
Therefore, the tangent of angle B is 67/78 in simplified, rationalized form.