No, since is not a whole number

Sum of exterior angles of regular polygon is 360°

When we divide the exterior angle by 360°, we get the numbers of exterior angle. Since, it is a regular polygon number of exterior angles will be equal to number to sides.

N = 360/50 = 7.2 [Number of sides of polygon]

7.2 is not an integer. So, it is not possible to have a regular polygon whose each exterior angle is 50°.