Two surveyors measure the distance across a river that they cannot cross. they drive two stakes into the ground and find that the distance between the stakes, the baseline, is 15 meters. they choose a pole as a landmark on the opposite side of the river. this forms a triangle, with the two stakes as two corners and the pole as the third corner. when sighting the pole from the two ends of the baseline, the two angles formed on their side of the river are 82° and 67°. the distance from the baseline to the pole calculated using the triangulation method is approximately