9.55 degrees.
step-by-step explanation:
the given angle is
1 cycle is equal to 2ฯ radians. so 4ฯ will be equal to two cycles.
5.166667ฯ-4ฯ = 1.166667ฯ
hence, this angle goes a little more than negative x axis.
1.166667ฯ-ฯ= 0.166667ฯ
hence, the reference angle is 0.166667ฯ radians.
1 radian = 57.2958 degrees
now, in degrees, this should be equals to 9.55 degrees.