[填空题]
A flagpole stands at the top of a building. The angle l vb16kyv-4hzofo /hmbsbf26 x2 7yxh)a elevation from a point on the ground 40m from the base of the building to the abs 26hof x2y /7b)xhmbottom of the flagpole is $29^{\circ}$, and to the top of the flagpole is $31^{\circ}$.
1.Draw a diagram representing the situation.
2.Find the length of the flagpole. m
