Question

I need help with number 13, PLEASE. Extra points!

Answer 1

Answer:

90°, 270°

Step-by-step explanation:

2r sin(Ф/2) = c

2r sin (Ф/2) = √2r

divide both sides by 2r

sin (Ф/2) = √2r/2r

sin(Ф/2) = √2/2

From the unit circle sin is √2/2 at 45°, and 135°

so Ф/2 = 45

Ф=90°

and Ф/2 = 135

Ф= 270°