General Maths Advance

[hyunah]

How would i write an appropriate equation for:
The radius of a circle is (x + 3) cm. A sector subtending an angle of 60◦ at the centre
is cut off. The arc length of the minor sector is a cm.

i don't get when it says sector subtending... how is it meant to look like?

Thank you in advance

[rhinwarr]

Sector is pretty much just a piece of the circle (imagine cutting a piece of a cake).
The equation for arc length is l=rθ.
l = a
r = x + 3
θ = pi/3 (you need to convert it to radians)
So the equation would be:
a = (x + 3) * pi/3