Question

Find the angle subtended at the centre of the circle by an are whose length is $15cm$ if the radius of the circle is $25cm$.

Answer 1

Given that

$l=15cm,r=25cm$

$\theta =\frac{l}{r}$

$=\frac{15}{25}=0.6radians$ ($1rad.=\frac{180}{\pi }$)

For $0.6rad.=0.6\times \frac{180}{\pi }$

$=34.36$ ($\pi =\frac{22}{7}$)

Hence the degree measures of the angle subtended at the center of the ciecle is ${34}^{\prime }36$