It is given in the question that the end of a pendulum with a length of 21 cm travels an arc length of 24 cm.
So here radius is 21 cm and the arc length is 24 cm .
Now we use the arc length formula , which is
[tex] s = r* \theta [/tex]
Where s is the arc length and r is the radius.
Substituting these values, we will get
[tex] 24 = 21 \theta
\\
\theta = \frac{24}{21}
\\
\theta = 1.143 radians [/tex]
And now we need to convert radian to degree, and for that we have to multiply by [tex] \frac{180}{ \pi} [/tex]
That is
[tex] 1.143 * \frac{180}{ \pi} =65.48 degree [/tex]
