28. Five mark exercise problem IV

The horizontal distance between two buildings is \(70 \ m\). The angle of depression of the top of the first building when seen from the top of the second building is \(45^{\circ}\). If the height of the second building is \(120 \ m\), find the height of the first building.

 

Answer:

 

The height of the first building is  .

 

(Note: Enter the number in the first box and the unit in the second box.)