Answer:
The the angle which the wire make with the ground is 1.280 radian .
Step-by-step explanation:
Given as :
The length of the wire attached to the top of building = OB = 70 foot
The distance of wire anchored from base of ground = OA = 20 feet
Let the angle made by wire en and ground = Ф
Now from , In Triangle AOB
Cos angle = 
Or, Cos Ф = 
or, Cos Ф = 
Or, Cos Ф = 
∴ Ф = 
I.e Ф = 73.39°
Now in radian ,
∵ 180° =
radian
∴ 73.39° =
× 73.39°
=
× 73.39° = 1.280 radian
Hence The the angle which the wire make with the ground is 1.280 radian . Answer