question_answer

In a circle of radius 42 cm, an arc subtends an angle of \[60{}^\circ \]at the centre. Then, the length of the arc is

A) 44cm

B) 24cm

C) 48cm

D) 46cm

Correct Answer: A

Solution :

Given, r = 42 cm and \[\theta =60{}^\circ \] \[\therefore \]Arc length \[=\frac{\theta }{360{}^\circ }\times 2\pi r\] \[\frac{60{}^\circ }{360{}^\circ }\times 2\times \frac{22}{7}\times 42\] \[=\frac{1}{6}\times 2\times 22\times 6=44\,cm\]