數學方位角問題(中三)

吾該幫我解答以下問題~~~~~~~THX!!!!!

1.Susan walks 50m at abearing of 210度,and then walks another 120 at a bearing of 120度.
(a)Find the distance between her starting point and destination.
(b)Find the ture bearing of her destination from herstarting point.(Give your answers correct to 1 decimal place if necessary)

(Hint: If C is a point on the path which is closest to A,then AC垂直BC)


2.In the figure,the compass bearing of B from A is S55度E and the distance
between A and B is 100km.A car goes along the direction N20度W from B.
(a)Find the shortest distance between the car and A.
(b)If the car goes at a speed of50km/h,how long does it take to arrive at the point
which is closest to A?
(Give your answers correct to the nearest minute.)