Answer: 11.46
Explanation:
Formula for calculating the length of an arc is theta/360 ×2Πr. Where;
length of the arc (L) = 9
Theta= 45°
L = theta/360 × 2Πr
9 = 45/360× 2Πr
9 = 1/8 × 2Πr
9 = Πr/4
Πr = 36
r = 36/Π
r = 11.46
Substituting we have,
9 = r × 45°
r = 9/45