Thread: Help with angles?

A river runs parallel to a block of flats. The roof of this block is 20m above the water level of the river. From a point R on the roof, looking directly across the river, the angle of depression of the nearer bank N is 43 degrees and the angle of depression of the farther bank F is 23 degrees. The bottom of the block of flats may be regarded as a point B.

a) Draw a diagram to display this information, showing clearly the points R, B, F and N and the angles of depression.

b)Calculate the width of the river, FN, correct to 3 significant figures

c) Calculate the distance from the roof to the near side of the river, RN, correct to the nearest whole number.

Im really stuck with how i draw the diagram? And then the method of how to work out the other questions. If anyone can help it'd be much appreciated.

sketch ...

could you please post the method of working out the other questions b and c
thank you

let ,





solve the system for and , then you can answer (c) using Pythagoras.