When it says that q = 19 cm, it means that the side opposite the angle Q is 19 cm long.
So, draw a triangle with a base parallel to the bottom of the page and the apex above about the middle of the base. Label the apex as P and the base as QR (Q to the left of R). The side opposite angle Q, which is the diagonal side on the right, is q = 19 cm. The side opposite angle R, which is the diagonal side on the left, is r = 16 cm. Angle PQR (ie angle Q), which is on the left of your diagram, is 56 degrees. You can find angle R (ie angle PRQ or QRP) using the sine rule - remember there can be two solutions with the sine rule - and side p using the cosine rule or the sine rule once you have all three angles (which must sum to 180 degrees, remember). You will then know all three sides and angles of triangle PQR.
