posted by lindsay .
Two pieces of wire are stretched from the top M, of a vertical pole to the points L and N on the horizontal ground, The angle of depression of L from M is 65 degrees. N is on the opposite side of the pole (from L) at an angle of depression of 72 degrees from M. N is 4m from the bottom P of the pole.
Find the length of each piece of wire
cos72 = NP/MN = 4/MN
MN = 4/cos72 = 12.94 m. = Length of wire to point N.
tan72 = MP/NP = MP/4
MP = 4*tan72 = 12.31 m.
sin65 = MP/LM = 12.31/LM
LM = 12.31/sin65 = 13.58 m. = Length of
wire to point L.