A circular field has an area 1256m^{2 ​}.A horse is tied at the centre of the field with the help of a rope 15m long.how much area of the field will the horse be able to graze?Also find the area of the remaining field. 

Answer : 

We have our circular field , As : 

Here length of rope = Radius of small circle that can be grazed by horse  = 15 m

And we know 

Area of circle  = $\mathrm{\pi } {\mathrm{r}}^2$
So,
Area of field graze by horse  = $\frac{22}{7}\times 15 \times 15 = \frac{4950}{7} =\mathbf{ }\mathbf{707}\mathbf{.}\mathbf{14}\mathbf{ }{\mathit{m}}^{\mathbf{2}}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{(}\mathbf{ }\mathit{A}\mathit{n}\mathit{s}\mathbf{ }\mathbf{)}$

Area of circular field  =  1256 m²
So,
Area of remaining field  =  1256  - 707.14  = ​548.86 m²                                  ( Ans )