Have you drawn a picture? Ignoring the height for the moment, you should be get a triangle with vertices at the building, Jenny and Michael. From the bearings you know all three angles in the triangle and you know one side (the distance from Michael to Jenny). Use either the sine law or cosine law to find the lengths of the other two sides (from Jenny to the building and from Michael to the building). Knowing those distances, use the angle of elevation and the definition of the "tangent" function to find the "opposite side" of a right triangle: the height of the building.