See the picture :D. Please help fast.

In ΔABD and ΔAEC

BE=DC (given) …(i)

Subtracting DE from both side of (i), we get

BE–DE=DC–DE

BD=EC

AB=AC (given)

∠B=∠C  (angle opposite to equal sides are equal)

Similarly, ΔABD≅ΔAEC

AD=AE (by c.p.c.t)

Hence proved

9.55 degrees.

step-by-step explanation:

the given angle is

1 cycle is equal to 2π radians. so 4π will be equal to two cycles.

5.166667π-4π = 1.166667π

hence, this angle goes a little more than negative x axis.

1.166667π-π= 0.166667π

hence, the reference angle is 0.166667π radians.

1 radian = 57.2958 degrees

now, in degrees, this should be equals to 9.55 degrees.