Vectors.Aproximate constants a,b,c.

So, i have 3 vectors:

A=2i-3j+ak

B=bi+j-4k

C=3i+cj+2k

where a,b,c are constants.

such that A is perpedicular on B and C, and the scalar product B*C=2.I have to estimate this constants using an iterative algorithm on Maple and then solve the problem using predefined function from Maple and compare the results.If you have an idea pls let me know.Thank you.Sry if I wasn't clear.