If the arcs of the same length in two circles subtend angles 750 and 1200 at the centre, find the ratio of their radii
Angle in radians = 
θ=
where θ is central angle, l=length of arc, r=radius
Therefore 
= 
= 
l = r × θ
Now, as the length is the same
Therefore, 
Therefore the ratio of their radii is 8 : 5
1