A) 78.5 cm
B) 4.7cm
C) 5.8cm
D) 23.0 cm

Answer:
The answer to this would be B.) 4.7 cm
Step-by-step explanation:
Arch = (Angle/360)(2[tex]\pi[/tex]r)
= (45/360)(2[tex]\pi[/tex]6)
= (0.125)(12[tex]\pi[/tex])
=1.5[tex]\pi[/tex]
≈4.71cm (assuming [tex]\pi[/tex] = 3.14)
Since an arch of a circle is just part of the circumference, you just need to multiply the circumference by the measure of the arch's angle divided by 360 (the angle measure of a circle).