Question

Find the angle subtended at the centre of circle of radius ‘a’ cm by an arc of length
`(api)/4` 𝑐𝑚

Answer 1

Length of arc =`(api)/4`cm

Radius r = ‘a’ cm

𝜃 = angle subtended at centre

arc length =`theta/360^@`× 2𝜋𝑟

=`theta/360^@`× 2𝜋𝑎

∴`theta/360^@× 2pia =(api)/4`

⇒` theta =(9pi×360^@)/(4×2pia)`= 45°