If △ ABC ∽ CAD, ∠ ACB = ∠ ADC = 90, BC = a, AC = B, ab = C, then CD is equal to Please use letters Thank you in advance

If △ ABC ∽ CAD, ∠ ACB = ∠ ADC = 90, BC = a, AC = B, ab = C, then CD is equal to Please use letters Thank you in advance

b/(c/b)=b^2/c