A surveyor can measure the width of a river (called b ) by setting up a point on the river bank (called C), then sighting straight across the river to a point on the other side (called A). Then walking 200m downriver from point C and setting up his transit (an instrument used to measure angles) at a point (called B). The angle at C is now 90 degrees. The angle where the surveyor is standing, parallel to the river and to the point across the river (A), is 20 degrees. What is the width of the river? I recommend drawing this out, so you have a picture to reference. Width = meters