Answer:
The the angle which the wire make with the ground is 1.280 radian .
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