I have a 7 foot diameter circle. I want to add 12 (same size) half circles attached to the outside of it. What size should they be?

Question

Need help, thank you in advance!

Answer 1

Each of 12 half circles is supposed to cover 360/12=30 degrees. The half of it is 15 degrees.

 

tan(15 degrees)=the radius of the half circle/radius of the original radius 

 

The radius of the half circle = radius of the original circle * tan(15 degrees)

                                        = (7/2) * 0.26794919243 

                                        =0.9378221735

Answer 2

perimeter of the given circle = 2π R =2 π x3.5 = π D=  7π

 

This perimeter is covered by 12 half circles each of diameter d

 

Total covered = 12 d

 

7 π = 12 d

 

diameter of each circle= 7π/12 foot