Answer:
u need to use the distance formula of coordinate geometry
Explanation:
let, a = > (-3, -4)-----( x1, y1 )
and b => (0,0)------( x2, y2 )
using the distance formula,
=> √[(x2 - x1)^2 + (y2 - y1)^2]
=> √[(0 + 3)^2 + ( 0 + 4)^2]
=> √[9 + 16]
=> √25 = 5
that would be 5 units