22. From the top of a 9m high building AB, the angle of elevation of the top of a tower CD is 30º C and the angle of depression of the foot of the tower is 60º. Find the height of the tower

• Distance between bldgs = 9/tan 60 = 3* root 3 m
  Ht of tower = 9 + (3 Root 3) * tan 30 = 9+3=12 mtrs
• 12 years agoHelpfull: Yes(45) No(5)
• let the distance b/w the two buildings are x,then tan 60=9/x,x=9/root 3;
  now tan 30=(CD-9)/(9/root 3);
  1/root 3=root 3(CD-9)/9;
  9=3(CD-9);
  9=3CD-27;
  36=3CD;
  CD=12.........
• 11 years agoHelpfull: Yes(25) No(3)
• Ans. is 18
  let the height of tower is h=h1+h2,(must draw fig.) from fig. we have h2=9
  angle of depression is 45,
  therefore,
  tan60=9/base(distance btw. tower and building)=>base=3*sqrt(3).
  now,
  Angle of Elevation, tan30= h1/3*sqrt(3)=>h1=9
  then total height h=h1+h2=9+9=18
• 11 years agoHelpfull: Yes(8) No(26)
• 9/sin60=x/sin30-->x=9/root(3)
  CD/sin30=x/sin60-->CD=3
  hence AB+CD=9+3=12
  Ans 12
• 8 years agoHelpfull: Yes(0) No(0)