Question

What will be the length of the remaining arc, if three-quaters of a circle of radius 20 cm is removed?
$\text{Take}\pi =3.14$

Answer 1

When $\frac{3}{4}$ parts of a circle is removed, only a quater part remains like this.


For the arc $AB$
Angle subtended by the radii $\theta =90$ degree
Diameter of the circle $d=2\times r=2\times 20=40cm$
$\therefore$ Length of the arc $=\frac{\theta }{360}\times \pi \times d$

$=\frac{90}{360}\times 3.14\times 40$

$=\frac{1}{4}\times 125.6$

$=31.4cm$