You can
put this solution on YOUR website!x-> exterior angle
int. angle -> 24 + 38x
ext angle + int angle = 180
x + 38x + 24 = 180
39x = 156
x = 156/39
x= 4 <-- ext angle
n-> no. of sides
ext angle = 360/n
n = 360/ ext. angle
n = 360/4
n = 90
i hope u did understand....godbless