So from
∆PQB, we have
PQ
tan
QB
lh
β =
=
 or l = h cot β
Step 5 is not required in this situation as exact values of the parameters h, l, α and β
are known Example 2 Let a business firm produces three types of products P1, P2 and P3 that
uses three types of raw materials R1, R2 and R3 Let the firm has purchase orders from
two clients F1 and F2 Considering the situation that the firm has a limited quantity of
R1, R2 and R3, respectively, prepare a model to determine the quantities of the raw
material R1, R2 and R3 required to meet the purchase orders