1.-On the shore of the lake,a surveyor measured a straigth line of 30 meters between point A and B.what is the shortest distance between the point C on the island and the point A on the shore if angle C A B = 23degrees and 50 minutes and angle C B A =67 degrees and 28 minutes.

2.-Find the angle B in an oblique triangle in which a =31,b =15,and c = 17.

3.-A triangular field with vertices O P Q has sides O P = 402 meters,P Q =388 meters,and Q O =254 meters.

find the perpendicular distance from the vertex P to the opposite side.

4.-In a rhomboid the obtuse angle is 123 degrees,the longer side is 50 mm,and the longer diagonal is 80 mm.Find the shorter side of the rhomboid.